I'm sorry that he's drinking again, and I feel your frustration.
If he's been to rehab before, he's got the tools to stay sober. He has to pick them up and use them however.
As far as his mental health issues, a psychiatrist can diagnose and prescribe the proper meds.
Is there any reason he can't be making those phone calls for himself?
I hope you are attending Alanon. It surely has saved my bacon more than once, and helps me with every day living.
Sending you hugs of support!