Hi, and welcome! I think most of us here can relate to everything you posted. We get it--all of it. How the drinking makes you feel, how you care about him, how hard it is to think about leaving.
No time for a long post right now, but you've gotten great feedback already. Learn all you can about alcoholism (just to help you look at what you're seeing, realistically), and get thyself to Al-Anon. Everything is spinning right now. Al-Anon will slow things down and help you get your head clear so you can take care of yourself and, ultimately, make whatever choices are best for you.
Big hugs, glad you're here.