If it's neurological, you will need medicine. Of course finding activities that you enjoy and getting the right amount of sleep is important.
I have mild OCD and severe anxiety and panic attacks started about 10 years ago. I really can't tell you how important medication is. And it's hit or miss, everyone is different, there isn't one medication that works for everyone, even if the symptoms seem the same. You may have to try several until you find one that helps and that you can tolerate.
Just know that there is help available, you're not alone. I think over 90% of the members on this forum are on medication, and they'll tell you how it's saved their life, literally in some cases.
If, on the other hand, it's just normal test anxiety, then studying, sleep, exercise and maybe a friend to vent with will help. I think you know which you have.
If you just need to vent, we're here, vent away.