You have to let him go, hes not gunna get sober because you want him to, hes only gunna do it if HE wants to. Hes being selfish and only caring about himself if he is lying and cheating and then toying with your mind. There are many others out there for you, this one sounds like he would bring you down. You have to ignore his attempts to contact you and move on, eventually he'll stop, and eventually you'll find someone else. Its been done many times. Good luck