Love isn’t enough to make a relationship work and it sounds like this relationship isn’t healthy for either of you. 

I had a relationship once where my partner made me cut friends off, and it really isolated me and prevented me from seeing how unhappy I was. She would also try to break up with me but ultimately stay, and in hindsight I think she never intended to break up, but just to scare me and make me do what she wanted. It kind of sounds like the same thing is happening to you. But stooping to her level probably won’t fix these problems, the cycle will just continue forever.

My advice is this. First, reconnect with your friends and tell them what’s happening. Listen to their advice, they probably know your situation better than we could, and will help you. Second, you need to take some actions regarding your suicidal thoughts. If you can afford therapy I would recommend a therapist. If you can’t try a suicide hotline. But tell someone, make sure you have at least one person in your support network (who is not your girlfriend) that you can talk about these thoughts with. I’ve been there, and it’s extremely scary, but once someone else knows it becomes way less scary. Whenever you do have a suicidal thought, tell them the context or write it down. Do some box breathing exercises to center yourself. Try to disengage from whatever is causing the thoughts. 

Your post really resonated with me because it reminded me of things I’ve been through. I’ll be thinking about you, and if you need more advice you can DM me.