If he is drinking as much as you say he just isn't available to you. That feeling you have of his pulling away from you may be when he is drinking. He can't think straight and will waffle a lot b/c of it. It isn't you, and the 180 might be to stay as detached as you can emotionally and engage only when he calls. Keep the calls short. This is going to take time. You will be able to read all your books.
I gave you the advice I followed when I got here. I never called my H, he was the one to call me. It was hard b/c we work at the same place and our offices are next to each other. I would listen to whatever he said and give little reaction - I tried not to get to involved in it.
I also set my own rule like this... if the convo was good and he was positive I stayed a little longer on the call, and I was sure to pick up his next call. If the convo was a downer, I shortened the call and didn't answer right away the next time. This way I did not have to say much about the R, no arguing, and at the same time I reinforced positive interactions and discouraged negative ones. This also helped me to monitor my own emotions and reactions knowing how things were progressing or not.
