Ladyhawke is so right. Only YOU can take care of YOU. It is perfectly okay for you to put yourself and your needs before his. If he is going to choose this path of destruction, you do not have to walk it with him. You have choices too. No contact is a great idea for clearing your head and allowing yourself to put the focus back on yourself. Very healthy, very FORWARD moving and definitely the path you deserve. Turn guilt away after 30 seconds. YOU aren't making the poor choices -- he is.
I found it helped me a great deal to look at myself in the mirror and say "You are NEVER going to live like that again."