Nice!
I generally advise against OChem during spring/summer terms simply because those are very intense courses with lots of complex content, and they become even more challenging when compressed into a shortened term. As
@Catalystik has pointed out elsewhere, it is possible to take those and do very well, but you have to really dedicate yourself to it and realize that those courses
are your summer. So think hard before you pull the trigger on that and make sure you're up to the challenge.
You should
always aim for 100s (and you should aim for 528 on the MCAT), but you also have to be OK with falling short of that. You haven't failed if you don't get 100, you've failed if you don't give your best effort.
Anxiety is tricky. You need to have enough anxiety to always be pushing for improvement, but you also have to learn adequate coping strategies so you can make your anxiety productive. Go to your school's counseling or advisement center, where they can help you with coping mechanisms and study helps to keep things in check. If you feel like your anxiety is becoming pathologic, you may need psychological or psychiatric help.
Med school
is like drinking from a fire hose, and residency's even worse. But your ability to handle the demands of your training will increase as you develop and deploy your coping strategies. You'll find that your capacity to manage the workload increases right along with the amount and intensity of the demands placed upon you.