Man I am like the exact opposite of you. I fly through tests at super speed, if I take my time i learned my performance is usually lower. My college algebra final had like 200 questions, i took it shaking and showing signs of psychosis. Managed to complete it in like 15 minutes and got an A.

It was kinda funny because i was literally shaking, crying and emotional. My hand writing was really really bad due to my hands shaking and yet i was still the very, first student done the exam by a loooong shot.

What i learned is you stick to your guns when it comes to testing. If you are slow and methotical be slow and methotical. I am sure you will get accomadations and don't be afraid to inform your professors about it too. Some of them will let you test even longer then the bonus time.

I had a data structures 2 exam where our professor made us hand write all our programs. It was a 7 question final it took me 47 pages (i counted) to answer the 7 questions and I finished the exam in around 2 hours. I was the first student done, the next student finished about 30 - 45 minutes after me. (i got an A)

I'm always the first student done in all my exams for every class, professors say its not smart. But every exam that i sat down and actually took time to answer i did bad on. SO basically just do school the way that is most comfortable for you. All the professors care is that you learn the material. They also don't want to stay in class all day waiting for you to finish your exam because alot of these professors have lots of work to do. Always communicate with your professor and tell him about yourself, if the school doesn't give you enough time he might give you even more time to work on it.