My therapist would say: that sounds like a lot of fear to have.

You know, it sounds like being a great student is a really important part of your identity and you're worried you might not be a great student any more. Ever think you're a great student who's not having a great time right now.

Have you talked to your tutors? I'm in England so sorry if that's not the right term. Can you tell them you're having a hard time? Is there any make-up work you could do to bump up your grade? Can you postpone applying to grad school and spread your work out over more time?