Does he have any close friends or family you can let know what is going on and maybe they could check on him?
When I kicked my X out, the lovely people at Celebrate Recovery, who are also good friends, told me they got this, and for me to take care of myself and my children. It was a huge relief I will forever be grateful for.
Many hugs. I thought my X was truly suicidal. In looking back, I realize he used that as manipulation and was never really suicidal, it was just my own fear. He was in a bad place, but not suicidal.
So if you truly fear that, call 911 and ask for a well check, which they will do. It's time for you to step back from all of this now in my opinion.
Many hugs.