I continued to work on themy review notes from yesterday.

"the" is ok here, but "my" is more natural, I think, since "the notes" could be notes that someone else prepared that you're just reading.

Everything was (clear / easy to understand) while I wrote the notes.

"clear" already has the meaning of understandable, so you'd probably either use "clear" on its own, or a different word like "easy to understand"

At last, I wrote down only the right answers only and read them with my eyes.

"with my eyes" is kind of an unusual thing to specify here. It makes you think of "how else would you read them?" (with braille maybe?). I think you might be trying to contrast to reading and saying the notes, but in English people will normally assume that just "reading" is reading quietly and would say specifically "reading out loud" if you decided to say them too.

I thought if I got used to these sentences, I wouldn't make any more mistakes.

I spoke very poorly today, and I realized that I overthink to makemaking English sentences every time.

Every word in my head felt (like it was in the mist / murky).

"murky" is a useful word here, it both has the metaphorical meaning of being unclear and also the connection to being able to describe a physical swamp as "murky" too.

I'm supposed to know how to say the words and sentences, but every single word I madesaid didn't make sense.

EI understood everything was clear to understandly while I wrote the notes.

Your sentence is understandable, but it is not worded naturally. English prefers active verbs.

At last,Finally / As a final step / I wrote down only the right answers to the quiz questions and read them with my eyessilently.

"At last" has a certain feeling associated with it. It's often used when you have been waiting for something, and it finally happens.
In this situation, you are stating what you did last, so the feeling is neutral. I deleted unnecessary words and added some for readers who may not know what answers you are talking about. We read aloud or silently.

I thought if I got used to these sentences, I wouldn't make morthe same mistakes.

Making "more" mistakes is very broad. It could mean new mistakes.

I spoke very poorly today, and I realized that I overthink to makemaking English sentences every time.

This is a hard stage to get through. One reason many young children learn to speak a new language more easily than adults is that they are not worried about making mistakes.

Every word in my head felt like It was difficult to find the mistwords I wanted.

On the one hand, the image in your sentence is poetic, and it could be expressed a little more fluently:
"The words in my head were hidden in a mist." or "The words I wanted were shrouded in mist."

On the other hand, what you describe sounds like "brain fog." Stress can cause this experience, and maybe the stress came from your high expectations for your performance.

I'm supposed to know how to say the words and sentences, but every single word I madeuttered didn't make sense.

"uttered" is less common that "said", but I think it could be used to emphasize the difficulty you were having

It was a very weird experience.

This is exactly what a native speaker would say!

No clue at all.

When I am back to regular days, I won't have as much intense time for English as nowstudying English intensively.

"intense time" isn't the combination I would use here. (I'd use it for riding a roller coaster or watching a scary movie. It describes the emotion within the time.)
You could use "focused time" or "time for intensive study"

At last, I wrote down only the right answers and re-read them with my eyes.

I spoke very poorly today, and I realized that I overthink towhen makeing English sentences every time.

Every word in my head felt like in the mistfoggy.

I'm supposed to know how to say the words and sentences, but every single word I madesaid didn't make sense.

When I am back to regular days, I won't have as much intense time for English as I do now.