I have stayed at my then- girlfriend's house for nearly one month, simultaneously looking for jobs in the newspaper.

This is simple past tense since she's not your girlfriend any more.

I found a company (ABC) was recruiting for an English Ttranslator, where an English Ddiploma and some experiences as an English Iinterpreter awere the prerequisites.

I graduated from high school and normally cwouldn't fitbe able to fill the position.

Human beings usually have a biglarge potential to develop a new skills for a living.

賛成しました。

I decided to take the job because I needed it.

This is past tense.

I found an advert phone number on the wall, phones and called a Ffake Ddiploma Mmaker.

また、

I found an advert number on the wall and phoned a fake diploma maker.

I became a university graduated student majoring in English after paying 200 Yuan two days later.

ハハ！

This wais another kind of traditional China's speedbehavior in China.

また、

- This is another kind of way things work in China.
- This is an example of the kind of speed at which China works.

Probably sSome of you may probably look down upon it as it was a deceptive behavior.

It was all done all for a living, however.

Perfect use of "however" here!

I immediately bought an English dictionary immediately,and read, and recited from it day and night within the two days.

I haved stayed at my then-girlfriend's house for nearly one month, (simultaneously) looking for jobs in the newspaper.

“Simultaneously” is unnatural (and unnecessary) here.

I felt a little bit anxious and could sense her frustration at not being able to help.

“Frustration at” is correct. You can see many examples here:
https://skell.sketchengine.eu/#result?lang=en&query=frustration%20at%20not&f=concordance

I found a company (ABC) was recruiting an English Ttranslator,. An English Ddiploma and some experiences as an English Iinterpreter awere prerequisites.

I had (only) graduated from high school and normally couldn't have fit the position | have met the requirements.

I decided to take the job because I needed it.

I found an advert phone number on the wall, phoneson a wall with a phone number for a Ffake Ddiploma Mmaker.

I became a university graduated student majoring in English after paying 200 Yyuan two days later.

This was another kind of traditional China's speed.

I don’t understand this. Maybe you mean, “This was another example of Chinese speed.”

Probably some of you may look down upon it as it was a deceptive behavior.

It was all done all for[for a living | to make a living], however.

I bought an English dictionary immediately, and read, and recited (memorized?) day and night withduring those two days.

“Recited (it)” means “repeated (it) aloud from memory” (背诵). I think you probably mean you “memorized” it (you committed it to memory).

I felt a little bit anxious and could sense her frustration atfor not being able to help.

you would be frustrated at "someone", and frustrated with/from/for "something".

I found a company (ABC) that was recruiting an English Translator, an English Diploma and some experience as asn English Interpreter awere the prerequisites.

Human beings usually have a big potential to develop a new skill set for a living.

I decided to take the job because I needed it.

I found an advert with a phone number on the wall, phonesthe number belonged to a Fake Diploma Maker.

Another two days later,go by and the boss of the company agreed to meet me at a coffee shop.