Advice?!

Okay so me and my fiancé live about 2 hours from my home town and my dad lives in my home town and there are no jobs and nothing to do there to better yourself keep in mind my dad had a bad past with drugs so I invited him to move in with me and my fiancé so he can find a job and better himself well he made plans to work and get himself a place up where I live so he got a job but he started drinking heavy and using drugs not hard drugs but still enough to mess him up so my dad has psychosis so if he does drugs and all it’s gonna make him worse and he will have another “episode” (seizures and hallucinations) and I tried talking to him he doesn’t think he’s done anything wrong but it’s really stressing me out and Idk what to do hes acting like a child and I love my dad but he can’t stay here and act like this please any advice is totally appreciated. I’m just real messed up about the whole situation