I can relate because I was undiagnosed and flipping toward the end of college. One thing that will help you is a studying routine--pick a part of the day when you have two hours free, and use it to work on just one class at first, then maybe think about adding another two hours for another class on another day of the week, even if you have to give yourself a big reward at the end of the session to motivate you to create the habit. That's really the secret to getting something done when you are sick--focus on one or two tasks, set up a big reward. Try it! ❤️ And remember, be gentle with yourself!