Eyeoftheholder, welcome to SR and glad you found your way here, although I am very sorry to hear about the situation(s) that bring you here.
It sounds like you have had a rough ride but you can acknowledge where you went wrong, what the patterns are, what you need to do to go forward- and that is one part of the battle friend. While in these situations, particularly with abusive alcoholics, we can become almost numb to the pain and think it's a 'normal' way of life if that makes sense, it takes us to a crazy place and it's not until we step outside we start to think about things, and yes that hurts.
Why do we love these men and continue to keep loving them no matter what **** they put us through- there are studies that draw conclusions but I myself have yet to fully understand why I stayed with an abusive (verbally and physically) alcoholic so long, and why I am still in contact with him now! It is to do with us deep down, but that's not to berate ourselves and say we are stupid, we care, we love, we want to help, we want happiness and to fix it and as you quite rightly pointed out we are codependent!
Read the stickies here they will give you valuable information, there are also some on abuse that will help you see the 'cycle' you are involved in and maybe get a better understanding of the whys and how's. Other people will share their experiences and please keep sharing yours and reading other posts as so many will resonate, even if just in small parts.
Look to al anon or other support groups, keeping busy is a good idea so as not to 'dwell' but most importantly take care of yourself. Let yourself feel sadness, anger, any emotion you need to as it is perfectly normal and ok. Reach out to people close to you that will care and understand, treat yourself kindly and keep coming back.
I can completely sympathise with you re the blocking- I tried this over and over and the longest period I have go NC is about 2 weeks. People will tell you here that no new contact = no new pain and reality is that's true, but you (and I) have to come to a point where we can do that, and sometimes these things take time.
Hugs to you, it's not easy, infact it's heartbreaking stuff to love an alcoholic, but you've come to the right place, please keep coming back.