Sweetie, those kinds of feelings are normal with breakups. Of ANY kind, not just with alcoholics. I had a guy in college (to whom I was engaged) break off the engagement over the phone. I broke off the entire relationship, and I was haunted for a while with that, "But WHY? I thought he LOVED me."
Honestly, I think he did for a while, but it wasn't a lifetime love for him. And that's OK. That's what dating is about. Sometimes the relationships just plain don't work out. Sometimes it's them, and sometimes it's us.
So maybe this guy did "love" you (by his definition, anyway) for a time, but it wasn't a lifetime love. And really, he didn't treat you great.
So take some time to lick your wounds and grieve, but don't feel like your life is over. You are still very young, and there are some awesome guys out there who will treat you the way you deserve to be treated.