Hi Firstmate and welcome to SR
There is a huge bunch of friendly people on this site with loads of experience with problem drinkers/alcoholics in one form or another.
It sounds to me that your BF is 'white nuckling'. He has given up drinking but is not getting help, so is desperately fighting with himself and mind to not drink. Can you imagine the kind of brain functioning that would have to take place to do this, its not surprising he has become distant with you. He can only concentrate on one thing and being sober is huge for him at the moment.
It is great that he is trying to get sober, he obviously realises that he has a problem, which is a good thing as many alcoholics are in complete denial. I am not too sure how long he will last though, as he does sound as if he is struggling a lot.
In the meantime perhaps you can look into Al-anon which is a programme for family and friends of alcoholic which will help you to make some sense of your feelings of rejection. Keep coming to this site too!