Yes, sometimes beer can seem so innocent. So he has a few beers after work! Doesn't he deserve that after a hard day of work, he needs to relax.
Well, it's up to him, of course, however 6 beers is (as you have seen) a lot of alcohol - and that is only what he showed you. That doesn't mean there wasn't other drinks at lunch or at other times during the day.
I think examining why you did ask him to leave and being firm in that is really helpful to you. Even if he had stayed though, there is no guarantee that you could have changed anything and in fact it's probably unrealistic to believe that. We just don't have that power over other people.
He has been away for a while and hasn't stopped drinking, he can make that choice anytime he wants to. Did he beg and plead to stay and say he would enter rehab right away? No. Keep that in mind. Alcoholics want to drink (not just like to drink - want to drink, are compelled to drink). Your interference in that is really just seen as being annoying and can put you firmly in the "enemy" camp at any time.
I can see with what you have written that you are struggling with this:
- honestly I know with how the whole thing went down I could not have done anything differently
- but I really wish I had realized how bad he has gotten before I kicked him out.
So you see the truth of it, but there is still that little voice saying - hey! maybe you could have fixed this! If love and care and worry and compassion could fix alcoholism, this forum would be a very quiet place. If ultimatums worked, again, very quiet.
The help he needs is from professionals, or from others that have walked that path - like AA. Those are his choices to make, of course, when and if he chooses to get sober.
Alcoholism in the house hurts children (and you).