Suicidal son

Lately I find my dominant feeling is anxiety/worry/concern for my depressed 18 year old son who expresses feelings about suicide. He now lives with his father because I had him move out due to his volatility with me and his siblings. He is a high school senior and isn’t going to school. He’s been hospitalized four times. He sees a psychiatrist and has been on many different meds and sees a therapist. My thoughts causing the worry are: am I doing enough? What if he commits suicide? If he does commit suicide, I’ll feel like a bad mother for having him move out (which I finally came to believe was necessary for the sake of my other children), not doing enough to help him (I have limited contact with him by his choice because blames me, even though I continue to reach out and strategize with his father), making the wrong choices (maybe I should have put him in military school when he was younger–I considered it and at the time I thought that would be worse for his mental health for a variety of reasons–I think he is gay and I was concerned his depression wouldn’t be properly treated there since he has never been at a stable place long on any medication) and of course I’ll be sorrowful to have lost my child. I have hope he will get better and I don’t know how to facilitate that. I’ve done many, many models on these thoughts. Continuing these thoughts has me focus on the past and the future, away from the people I’m with at present (clients–I’m a divorce mediator and it makes a big difference being able to focus, my other two children who need me since their father doesn’t give them much emotionally, myself–I often feel burned out). It does feel overwhelming.