I'd think about things you can do to establish boundaries and protect yourself while you wait for him to come out of the fog or you to be ready to deal with this. Some thoughts I have -

1) Request he speak to his gf about her NOT contacting you. Let him deal with her - chances are she is pissed at him for not making a move and trying to pressure him. Let him deal with being angry at her, rather than making it a fight with you instead.
2) Change the locks and let him know that he needs to arrange visitation or a time to get to any of his things, etc in advance.
3) How much money did he leave in the house? I wouldnt get too aggressive about that, since he is supporting you. Maybe just move it so that he has to ask you about it if he wants it.
4) See an atty, find out your rights and options, then let it simmer for awhile without telling him - just give yourself some time.

Faith is, at one and the same time, absolutely necessary and altogether impossible.
--Stanislaw Lem