Go to TA/Professor office hours, they have to help you study, plus other students there ask very good questions which you might have not taught of. Think of it as group study with a moderator.
Second, you used the word suicidal.. you're electing to study. This is a trill for most of us, we love it. We love staying up all night studying for a test, etc. We know we could have successful satisfying careers in other fields but we genuinely like the torture of going to sleep 4am, to wake up 6am to cram for that immunology midterm, etc and finding out how we did afterwards. Throughout this process you are an individual who is to stand on your own two feet. You don't need anybodies help or pity. Group work is seriously over rated as 50% of the time they turn into social hour (which sucks!). Don't think you're unworthy, even if people are studying behind your back, go study alone, learn your stuff real well, discover a twist that you're sure the group didn't see, and tell yourself, "hey, I know something they don't." You can't believe how much quality time is waisted in groups when someone is trying to explain a concept to the group members, then the group members regurgitate the concept to have their understanding confirmed. If you don't understand a concept, ask the TA/Professor (remember that you'll need LORs 😉).
The time your stressing about all this stuff you could have been studying 🙂.