It sounds like you are feeling extreme anxiety over the future. Have you thought about counseling for yourself? It could be a clergy member if you have a faith which you follow or if you don't have one, then I recommend speaking to your doctor who can refer you to a good therapist.

Certainly we have no control over others and must deal with the choices they make.

I have a good friend who has that. He is a vet and also has ptsd and depression but as long as he is taking his medication, he is great to be around.

We will keep you and your family in our thoughts and prayers. We hope you can find some peace! Keep us posted.

God Bless

It sure is hard when we have a loved one with schizophrenia. My brother is one of them too. It's hard to know what they are really thinking. My brother grew up not sharing I think out of fear, and being locked up for it. But if the meds he was on were going okay and he took them he was easier to talk with, yet I have worked with some others like him and sometimes one can say the wrong thing and send them into an episode.
Give yourself a break and deal with you and it's effects on you too. Also give yourself a bid pat on the back because taking care of someone with schizo tendencies is tough but suicidal ones are even harder to get back to reality and be able to enjoy life again even though they only see their disease and don't like themselves sometimes because of it.
Like bobinmaine said we can't control them but it sounds like you are doing all you can so be proud of that even if the day comes and he does succeed in suicide, you need to be proud of you for taking care of him when others can't or don't know how. Another thing could be checking out someone to come in the house to check on him, like caretaker, or another family member. I hope you find some relief soon and don't burn out. Hugs and prayers to you for the strength to take of your loved ones and yourself.