Last Yesterday, my roommate was so mad,angry and it turned toit on me.

I think this is what you mean but I'm not sure.

Now I'm SO mad today!

I thought I could takecatch a breath after the exams but, it wasn't like what I thought it would be.

But, it wasn't like what I thought.

This is an incomplete sentence so I deleted it and added it to the previous line.

I had a meeting to discussing the a presentation.

Because we had already separated the work into six parts, everyone had had their own job to do.

As a result, I expected it didn't took much timethat it wouldn't take a lot of time to finish.

However, the factReality was cruel, however.

We avoid using "however" at the beginning of sentences when writing.

Some teammates said that they had temporary jobs, so they were absent.

I totally understand, because it is always busy at the end of a semester, but someone just had disappeared for about four hours.

Yikes! That's rude!

She didn't noticeeven tell us in advanced.

or

She didn't notify us about it in advance.

Me and tThe other member and I organized and revised the entire presentation byon our own.

We always state other people first before mentioning ourselves in written English.

I spent more than two hours than I had expected, because some parts were like the finished products of ctrl C and ctrl Vjust copy and pasted. When everything was done, the one who disappeared came out,back and said s, "Sorry, I was busy at that time."

Wow.

Daiary 1/4

dairy = 乳品 😁

Last Yesterday, my roommate was so mad, and it turned to menow it’s my turn.

I thought I could take acatch my breath after the exams., but…

B…but, it [wasn't like what I thought | didn’t turn out as I’d expected].

I had a meeting to discussing the presentation.

As a result, I expected it diwouldn't tookake much time.

However, (the fact) reality was cruel.

Some teammates said that they had temporary jobs, so they were absent.

She didn't noticefy us in advanced.

Me and tThe other member and I organized and revised the entire presentation byon our own.

I spent two more two hours than I expected, because some parts [were like the finished products of ctrl C and ctrl V | had been copy/pasted]. When everything was done, the one who disappeared came out, and said s, “Sorry, I was busy at that time.”

Daiary 1/4

dairy = milk, cheese, butter
diary = daily journal

Last Yesterday, my roommate was so mad, and it turned toaffected me.

I'm not really sure what you mean, but I guess it's something like: because they were very mad, I got mad as well (or I stopped having a good time).

I thought I could take acatch my breath after the exams.

https://writingexplained.org/idiom-dictionary/catch-your-breath

Because we had already separated the work into six parts, everyone had had their own job.

As a result, I expected it diwouldn't tookake much time.

However, the fact was cruelit went really bad.

there are more possible versions, I went with something like: I expected it would go well, it actually went bad.)

Some teammates said that they had temporary jobs, so they were absent.

I totally understand, it is always busy at the end of a semester, b. But someone just had disappeared for about four hours.

I separated into two sentences because I understood it like this: ”Some people have jobs, and I understand they are busy. Someone else disappeared for four hours.” (if it's actually the same person, you could go with: ”I totally understand..., but they just disappeared for four hours”)

She didn't notice ingive us any advanced notice.

to notice = to observe (”I didn't notice you were here”)
to give notice = to let others know

Me and the other member organized and revised the entire presentation byon our own.

I spent more two hours than I expected, because some parts were like the finished products of ctrl C and ctrl V. When everything was done, the one who disappeared came out, and said ”sorry, I was busy at that time”.