:/ need to vent i guess

I don’t know what to do. My gf and i have been dating for four months now. She struggles a lot with depression and mental health in general. (She is my first girlfriend to preface.) But she stopped taking her medicine two and a half weeks ago and i can tell a difference but she can’t. We talk about death everyday. And if we don’t i would consider it a good day. I mention she needs to get help but she says she is in therapy. Her therapist knows her very well and says she would hospitalize her. I don’t know what to do. I don’t want to leave but she’s told me at-least twice now that she had a date, intent and a plan to commit. I told her i feel like i can’t sit here and not do anything. I can’t sit here and just continue to date her if we can’t find a solution or a plan. because at the end of the day how am i supposed to live with myself if she were to do it? And when i mention or try to call her family she gets upset. I need help please I’m super overwhelmed and haven’t been sleeping because she said one day that when i was sleeping would be the best time to do it.