2004 was thea key year in my life and, but I don't want to say somdiscuss some of the unpleasant things in details.

It was also the year of my thirty-seven and I had many thoughtsth birthday and I was thinking a lot about the situation at that time.

iIt seemed that I could see my life after my retirement and it would be asjust the same as it was just at that moment.

This was definitely was a terrible thing for everanyone and I was not willing to accept it.

So what could I do the next?

Obviously, I couldn't quit my job, it was what I oncebecause I had tried hard to look forget it, but I was not satisfied with the situation in front of me either.

After a lot of thinking, I decided to take the National jJudicial eExamination to gain a lawyer's qualification.

Waiting for thatsuch a long time to take an exam was really painful, and you couldan't imagine that kind of suffering.

When I knew the result of the examfound out my exam results, I was filled with emotions and a kind of grievancef.

Although I eventually wasn't to be a lawyer, things itselfdidn't become a lawyer, it was a big encouragement to me because it let me find confidentce again.

2004 was the key year in my life and*but* I don't want to say some *of the unpleasant things in details.*

It was also the year of my thirty-seventh birthday and I had many thoughts about the situation at that time.

Are you talking about your age? If it is, this will sound a bit more natural.

it seemed *like* I could see my life after my retirement and it would be as the same as it was just at that moment.

Obviously, I couldn't quit my job, i. It was what I once tried hard to look for, but I was not satisfied with the situation in front of me either.

but at that time, I just had *a* college degree and the exam required *a* bachelor's degree, so I had to learn*study* three years for it.

Although I eventually wasn't to*going* be a lawyer, *things* itself was a big encouragement to me because it let me find *my confidentce* again.

[..eventually wasn't going to be a lawyer...] = would not happen in the future

[..this itself was a big encouragement...] = It is implied that the exam is what gave you confidence, so it was that one thing exactly.

When I reassessed something*a moment* that was similar to this, the conclusion was that all the tough situations was caused from our*by people* slacking off.

"a moment" sounds more natural, but what you said would still be correct.
"our" would be too vague. Who would be slacking off? Is it you slacking off or people in general?

If I got my university degree in time, I would have the exam qualification in advance and could promote *myself to a* professional title many years ahead of time.

2004 was the key year in my life and I don't want to say some unpleasant things in detailsthat I don't want to discuss in detail happened.

"A key year" sounds more natural to me, but this is fine.

It was also the year of my thirty-seventh year and I had many thoughts about the situation at that time.

"I was 37 that year" would be perhaps more natural, but "my thirty-seventh year" would be acceptable if you're going for a certain effect.

iIt seemed that I could see my life after my retirement and it would be as the same as it was just at that moment.

I would introduce "that" since the clause is relatively long.

Obviously, I couldn't quit my job, because it was what I once tried hard to look forobtain, but I was not satisfied with the situation in front of me either.

"Look for" is fine, but "obtain" seems more precise. To me, "looking for" a job refers more to the process of a job search than to the end result.

After a lot of thinking, I decided to take the National judicial eExamination to gain a lawyer's qualification.

bBut at that time, I just had a college degree and the exam required a bachelor's degree, so I had to learnstudy for three years for it.

While "college" can refer to secondary school or to a trade school in certain parts of the English-speaking world, "college degree" suggests that you are referring to an undergraduate degree. That's the same as a bachelor's degree, so the sentence doesn't really make sense to me.

Waiting for thatsuch a long time to take an exam was really painful, and you couldn't imagine that kind of suffering.

In fact, I couldn't spend that longmuch time just for preparing afor an exam,: I just used half a year to do it and in the rest of time, I took some part time jobs like copywriting, and art designing while wentgoing to work.

When I had my bachelor degree after three years, I took the exam, and fortunately, I passed it.

When I knew the result of the exam, I was filled with emotions and a kind of grievance.

"Grievance" is fine but needs clarification, especially one usually has a grievance against something in particular.

Although I eventually wasn't to be a lawyer, things itself wasthemselves were a big encouragement to me because ithey let me find confidentce again.

When I reassessed something that was similar to this, the conclusion was that all the tough situations wasere caused fromby our slacking off.

If I got my university degree in time, I would have had the exam qualification in advance and could have promoted my professional title many years ahead of time.

For most people, it is too late to become aware of that you have to work hard to catch up!

I have wasted twenty years, and I have to get them back.

The average English teacher would interpret this as a comma splice that needs to be fixed by adding a conjunction or punctuation that separates clauses (period, semicolon, colon, etc.). I think in this situation, the sentence may be stylistically acceptable, but I would still discourage someone from using it unless it were already demonstrated that they knew how to use such run-ons judiciously.