For me the issue was external factors. Don't ignore your social and romantic needs, don't try to do more than it is required of you to impress. Don't define yourself purely through your academic abilities, as annoying as that might be.

Do the bare minimum, but do it, and do it now. Try to collaborate with others, it will help you understand you are on the same level as them and you don't need to turn every lab report to a thesis-like endeavor.

Therapists can be hit or miss, but I think it might help you to talk to someone if that's a possibility. Some times in life you don't have level-headed impartial friends to give you good advice, and imo a good therapist would do just that. Help you see more clearly from a different perspective.