Only a very very small percent of concussions cause a cognitive deficit. If you are not engaged in contact sports or risky activities, you have more risk driving in a car.

Being anxious is a greater risk because it reduces your coordination and affects judgement. Doing exercise where you can smack your head on the floor is not wise.

What are you pursuing in university ? Some disciplines are anxiety inducing. Learning to moderate your anxiety levels at a more serious level may be crucial.

Proper nutrition can improve your tolerance to anxiety inducing issues. Exercise is good but it sounds like it is inadequate for your needs.