Well, I agree, see if you can get him to go get some help.
The other thing to do is love and support him as you can, while still honoring your own wishes and needs. People who want to die, are in pain. The only reason anyone would think of suicide is that there is some kind of internal pain that is worse than offing onesself. . . .
So sorry for his pain, (I'll keep him in my prayers) Belle,