I have been studying for TOEIC

I have been studying for TOEIC over the last four months/for more than four months, (this 'over' can mean 1.more than 2.throughout)
because The its score of it is needed/a requirement to when transferring to the the another university.
TOEIC is an English test which includes the sections for listening and reading parts.
The full maximum score of it is 990 and I need to score/a score of at least 950 score.
I just have a last final test in just 3 weeks.
I'm a little/bit (one or the other, not both) nervous and stressful stressed that I have/about having to be  almost perfect, and not to make any mistakes in the test

I hope I haven't freaked you out then with all the corrections!  Notice some of them are just alternative suggestions