When I in my middle school，my English teacher is very nice.She is a middle-aged woman about 60 years old.She teached me very paitently.ANd because of she liked me very much,my grade is better than anyone especially the English record.But,we changed our teachers because we go up to higher grade.The new teacher doesn‘t like me so I lost intrest in English.

When I was in middle school，I had a very nice English teacher who was about 60 years old. She taught me very patiently. Because of she liked me, my grade was the best in the class. However, when I moved up a grade, I got a different teacher. My new teacher didn't like me as much and so I lost interest in learning English.

As time goes on,I found out that learning English well is very important.Then I Start to learn it again and hope that I can insist on learning but not quit in halfway.

As time went on, I realized that learning English is very important. I started learning again and hope that I can persevere and not quit halfway through.

When I in mywas in middle school，my English teacher is very nice.She is a middle-aged woman about, I had a very nice English teacher. She is an older woman who is around 60 years old. She teachedaught me very paitiently.ANd b Because of she liked me very much, my grade is better than aneveryone especially the English record.But,we changed our teachersin the class. Our teacher changed because we go upadvanced to a higher grade. The new teacher doesn‘t like me, so I lost interest in English.

"ANd because of she liked me very much,my grade is better than anyone especially the English record"

I don't really understand what you want to say here. Also, usually you should not begin a sentence with "and" or "but".

As time goeswent on ,I found outrealized that learning English well is very important.Then I Sstarted to learn it again and hope that I can inpersist on learning butand not quit in halfway.

When I in mywas in middle school，, my English teacher iwas very nice. She iwas a middle-aged woman about 60 years old. She teachedaught me very paitiently.AN And because of she liked me very much, my grade iss were better than anyoneeveryone else's, especially themy English record.But,we changed our teachers because we go up to higher grade.The newgrades. But when I went to high school, my new English teacher doesn‘idn't like me, so I lost interest in English.

As time goes on, I found outind that learning English well is very important.Then I S I'm starting to learn it again and hope that I can insistkeep on learning but not without quit tin halfway.g.

When I in mywas in middle school，, my English teacher iwas very nice. She iwas a middle-aged woman, about 60 years old. She teachedaught me very paitiently.ANd because of Since she liked me very much, my grade iwas better than aneveryone; especially thein English record.But,we changed our teachers becaus. Our teachers changed when we we gont up to a higher grade. The new teacher doesidn‘t like me, so I lost interest in English.

Just a note:
I believe schools (at least in America) have traditionally taught students not to begin written sentences with the words "And", "But", or "Because", etc.

https://www.merriam-webster.com/grammar/words-to-not-begin-sentences-with#:~:text=Never%20begin%20a%20sentence%E2%80%94or%20a%20clause%E2%80%94with%20also.&text=Teach%20the%20elimination%20of%20but,the%20beginning%20of%20a%20sentence.&text=A%20sentence%20should%20not%20commence,%2C%20or%20however....

I personally don't think it's a problem, because communicating meaning is the most important thing to me (with which I think you are doing well!). In the spoken language, it does not matter.

As time goeswent on, I found out that learning English well is very important.T I then I Sstarted to learn it again and. I hope that I can inpersist oin learning but not without quit ting halfway.

The sentence, "I then started to learn it again." could also be written in other ways (all are correct!):

"I then started learning it again."
"Then, I started to learn it again."
"Then, I started learning it again."