From my experience speaking to others with anxiety, it's always funny to see that they all have almost flawless academic records, weird huh?
I would say that you feeling happy in your general self is the most important thing, it's amazing that you have anxious tendencies but you have the self-control to not take them to a higher level. Personally I didn't stop when I should have, and it all spiralled into constant irrationality to a point where I needed two doses of weekly counselling.
I think the pressure to do well in your exams is just getting to you a little bit, but it should settle down once you get into the exams routine. It will pass!
Good luck, I'm sure you'll be fab