A Disasterous Week

The adjective form of "disaster" is "disastrous," and you need it here because it looks like you are using it to modify "week." You could also write "A Disaster of a Week" though.

Firstly, for the last two days, I amhave been sick and sleeping at home. ¶
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You need to use the present perfect (have + the verb participle) since this is an action that is continuing from the past until now.

Secondly, I made the wrong model layout for Lase and cut it.

I still can't believe it how I can do such a kind of. How did I make such a mistake.?

One "makes," not "does," mistakes. The sentence also sounds like it contains two different clauses, which haven't been separate correctly.

Thirdly, I had a second presentation this wWednesday and I couldn't make it.

I really want toed show to my project before the final presentation.

It sounds like you are describing how you felt back then, so we need the past tense.

Now, I am doing something that I hate, saying to myself, "A lot of people didn't show up, not just not me."

Be careful with the placemust of "just," because it can change the meaning of the clause.

I plan to graudatduate at the end of this semester, so t. This is the last project, but it had been really hard to get into this projecit.

To me, it doesn't make sense to use "so" because it doesn't obviously follow from what you wrote that this is the last project. You also should take out the second instance of "project" in the second sentence, as it feels redundant when it is repeated again so soon and when we already know what you are referring to.

My concept and the form of my building hadve been done, but I had feelt lost.

You should use "have been done," because you are describing the project as it is now. For the same reason, you shouldn't use the past perfect ("had felt") to describe how you feel; instead, you could use "feel," "am feeling," or "have felt."

There is a lot of things that need to be wrapped out and time is running out.

A Disaster of a Week

or you could have "a disastrous week", as some others have commented. "A disaster week" is something that a native speaker might say sometimes, but usually as a shortening of "a disaster of a week".

This week whas been a disaster.

This might be a dialectical thing in English, but to me, if the week's not over yet, you have to say "has been", rather than "was".

Firstly, for the last two days I am've been sick and sleeping at home. ¶
¶
¶

Again, "have been" sounds more natural to me here. If it was "on the last two days of the week", you could say "was", but because "the last two days" leads right up to now, "has been" sounds better.

Secondly, I made a wrong model layout for Lase and cut it.

You just need the indefinite article "a" here.

I still can't believe it how I can do such a kind ofould have made such a mistake.

Because the mistake is in the past, "could have made" sounds better than "can make" (which would be the correct way of saying it in the present tense). If you made such mistakes *regularly*, you could say, "I still can't believe how I can make such mistakes," but it sounds like that's not the situation!

Thirdly, I had a second presentation this wWednesday and I couldn't make it.

Days of the week start with capital letters :)

I really want to show topresent my project before the final presentation.

You can use "show", but you'd need to say who you'd be showing it to (e.g. "I want to show my project to my team") – without saying that it sounds incorrect. If you don't have a specific audience, then another verb like "present" should be used (even though here it sounds a bit repetitive because of "presentation" being in the same sentence).

Now, I am doing something that I hate, saying to myself, "A lot of people didn't show up, just nonot just me.

"Just not me" sounds like you were the only one who didn't turn up, which sounds wrong given the first half of the sentence. "Not just me" is more like "I wasn't the only one [who didn't turn up]", which seems more correct here.

I plan to graudatduate at the end of this semester, so this is the last project, but it had beenwas really hard to get into this projecit.

"Had been" is used as "the past of the past", so you use it more in a past-tense sentence to talk about things even further in the past. This sentence is in the present tense, so it sounds better to use "was".

My concept and the form of my building had donebeen finished but I had felt lost.

There isare a lot of things that need to be wrapped outup and time is running out.

A Disasterous Week

Like others pointed out, "A Disaster of a Week" also works too

Firstly, the lpast two days I am've been sick and sleeping at home. ¶
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"last two" and "past two" both work, but depending on context one might sound better
You can also say "First of all" instead of "Firstly", but I think both work
When it comes to "I've been sick" vs "I was sick", they have different implications - "I was sick" implies that you're no longer sick currently, but "I've been sick" implies that you still may be sick, or only very recently got better

Secondly, I made the wrong model layout for Lase and cut it.

I haven't heard of "Lase" and looking it up just redirects me to laser, so I'm honestly not sure if it's a program I can't find or a typo; if it's the name of some kind of program then that's all, but if it's meant to be "laser" then it should be "for the laser".

I still can't believe it how I can domade such a kind of mistake.

There's a lot of options depending on if it was meant to be one simpler sentence or two sentences combined into one.
Generally speaking all the corrections from others are correct, and there isn't a lot of difference in meaning between them. However, if it's broken up into two sentences (for example: "I still can't believe it. How did I make such a mistake?") it comes off as more emphatic to me.

Thirdly, I had a second presentation this wWednesday and I couldn't make it.

I really want to show to my project before the final presentation.

Whether or not it'd be past tense depends on if there's more presentations between the one on Wednesday and the final one.
If there are, it'd be present tense since you're still hoping to present it. If there aren't, it'd be past tense since you can't hope for it anymore but you hoped for it in the past.

Now, I am doing [a/the/that] thing that I hate, saying to myself "A lot of people didn't show up, not just not me."

Any one of those three would work, but they have different implications.
"a thing that I hate" implies it's one of many things
"the thing that I hate" and "that thing that I hate" both imply something more specific and reoccurring, but "that" can be more emphatic and impersonal than "the".

I plan to graudatduate at the end of this semester, so this is the last project, but it had's been really hard to get into this projecit.

You could still write out "this project" at the end, but it feels a bit redundant - "it" sounds better.

My concept and the form of my building hadare done but I had feelt lost.

There isare a lot of things that need to be wrapped outup and time is running out.

Firstly, the last two days I amwas sick and sleeping at home. ¶
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¶

Secondly, I made a wrong model layout for Lase and cut it.

I still can't believe it how I can domade such a kind of mistake.

Thirdly, I had a second presentation this wWednesday andbut I couldn't make it.

I plan to graudatduate at the end of this semester, so this is the last project but it had been really hard to get into this project.

My concept and the form of my building hadwas done but I had felt lost.

There isare a lot of things that need to be wrapped outup and time is running out.

A Disasterous Week

Firstly, the last two days I amwas sick and sleeping at home. ¶
¶
¶

"Firstly" isn't incorrect, but I personally would use "first, second..." etc.

Secondly, I made the wrong model layout for Lthe laser and cut it.

Is "Lase" a particular machine or something?

I still can't believe it how I can do such a kind ofthat I made such a mistake.

Another option: "I still can't believe I made such a mistake."

Thirdly, I had a second presentation this wWednesday and I couldn't make it.

The "I" before "couldn't" isn't necessary since you already have it earlier in the sentence.

I really wanted to show to my project before the final presentation.

Now, I am doing this thing that I hate, saying to myself, "A lot of people didn't show up, just not me."

I plan to graudatduate at the end of this semester, so this is the last project, but it hads been really hard to get into this project.

My concept and the form of my building hadare done, but I had feltfeel lost.

Since you're talking about the present state of your building and feelings, use present tense.

There isare a lot of things that need to be wrapped outup and time is running out.

A Disasterous Week

First of ally, the last two days I amwas sick and sleeping at home. ¶
¶
¶

Secondly, I made wrong the laser model layout for Lase andand also cut it.

You mean a laser layout?

I still can't believe it h. How I can do such a kind ofI make such mistake?.

Or, "How could I make such a mistake?"

Now, I am doing a thing that I hate, saying to myself: "A lot of people didn't show up, just nonot just me.

I plan to graudatduate at the end of this semester, so this is the last project but. However, it hads been really hard to get into this projecit.

It's better to split the sentence and reference the semester in the second part.

My concept and the form of my building had been done, but I had felt lost.

There is a lot ofare many things that need to be wrapped out and time is running out.