I really understand where you are coming from as I am in the same place as you with my ex boyfriend.
This week has been quite hard for me and I can't understand why I'm feeling weak while he's acting strong. We haven't spoken at all for about 2 weeks but 2 weeks ago he was giving me an ultimatum that I need to stand by him and be 100% in the relationship or he is going to walk away! Is he kidding me? After all I have done with sticking by him, going to therapy with him, giving up drinking with him (I am not a drinker I just like to have a glass of wine every once in a while when we went out to dinner) going to church with him, and just being there to support him. Now he is playing the victim that I am not good enough because he needed me and I wasn't there to support him while he would verbally abuse me and isolate me from my family and friends.
I understand what you're going through and the pain..... trust me I do. I think we become addicted to them because we are so worried that something will happen to them if we are not there to "save" them. Also worried that they will blame us and as good people, we want to help and can't think of living with that guilt if something happens to someone we truly love.
Stay strong! And just know that there are other people going through this. Your feelings are real, feel them... but remember what you deserve... and it sure is not this.