Roy in a mood

I had Roy at my house Friday night cause I wanted to give him a break from the 3 day weekend at home.  Had him most of Saturday.  However once he got home his mood plummented and he wont talk clearly on texts, at church or on facebook.  He is threatening to kill himself and is angry and wont tell me why.  I am pissed but at the same time trying to accept this as who he is, that he cant see the good part of life and is just "stuck" in the now.  Part of me wants to tell him off, the other part wants to accept him and love him.