[24M] facing a deteriorating relationship with [23F]

I could really use your advice. I’m a 24-year-old man in a relationship with a 23-year-old woman I deeply care about, but our relationship has always had its challenges. I left an abusive home environment and was invited to stay with her before we started dating. At the time, we were both struggling—she came from a broken family too. Eventually, we began dating, and everything seemed great for a while. However, her mental health took a downward turn, and mine followed suit. I became so focused on supporting her that I neglected my own well-being, sacrificing friendships, family ties, and hobbies in the process. We eventually moved into our own apartment, which brought some improvement, but lately, it feels like we’re dragging each other down, and we've been fighting a lot. My girlfriend has been experiencing severe suicidal thoughts and frequent panic attacks, which has become very difficult for me to handle. I’m at a point where I’m not sure how much more I can take. I fear that breaking up would have a devastating effect on her, yet I’m also uncertain about what my future holds. Just today, she had a breakdown and expressed that she doesn’t want to lose me but also doesn’t want me to suffer any longer. Hearing that really overwhelmed me emotionally—I found myself crying for the first time in years. I feel lost and frightened, unsure of what the right next step is. I would appreciate any advice you can offer.