Time is so fast. Time is so fast.

Suggestions: Time passes very quickly. Time flies.

Time is so fast.flies. I agree with @JoeTofu Time flies. I agree with @JoeTofu

Time is so fast. Time is so fast.

This is good! If you want to sound more natural, Americans tend to say "Time passes so quickly" or "Time goes by so fast" rather than just "Time is so fast."

Today's examination was finished. Today's exam was finished.

Today's examination whas finishbeen completed. Today's examination has been completed.

Today's examination was finish.ed. Today's examination was finished.

Today's examination was finishis over. Today's examination is over.

We often speak of something being "over" when it is finished or done. It works well here, I think. It conveys the feeling that the exam is behind you now and part of the past.

Today's examination was finish, I reflected on my year. Today, I reflected on my year.

It seems like by "examination" you might mean something more like "reflection?" In English, "examination" means "test" and usually has an academic connotation. Athough it can sometimes mean "investigation" (to literally look closely at something in order to learn something), we usually use "reflection" when we talk about figuratively looking at something (for example, we examine ourselves or we examine our accomplishments). You could instead say "Today I did a reflection" or "Today I reflected."

Today's examination whas finished. Today's examination has finished.

Looking back, I feel like I didn't accomplish anything this year. Looking back, I feel like I didn't accomplish anything this year.

I feel likeEverything seems vast and hazy. Everything seems vast and hazy.

IMy feel likings are vast and hazy. My feelings are vast and hazy.

Not quite sure of the sentence

I feel likeEverything feels vast and hazy. Everything feels vast and hazy.

I’m guessing this is what you mean.

I feel likeMy impression of the year is vast and hazy. My impression of the year is vast and hazy.

I'm guessing that you mean that the year seems vast and hazy as you look back. I suggest "impression" to reflect this is how it seems. (Other people have interpreted this sentence differently, and I wanted to offer another interpretation.)

I feel like vast and hazy. I feel vast and hazy.

I feel like vast and hazy. I feel vast and hazy.