Hey - I'm really sorry to hear how hurt and upset you are (completely allowed and completely understandable!!) Forgive the essay but it MAY help?
I thought something I was told by a friend of mine might help a little bit. I was telling her how, although my oh is lovely and has been great, he went back to work the very next day, and had to be told to come home by the friends I work with (2 of them knew). He is usually SO great about everything and he still is, I was completely gobsmacked by how insensitive I thought he was being - like he wasn't grieving or unhappy at all. I had to REALLY sit him down and say to him - listen, this is what it's like for me, this is how I feel. HE SO DIDN'T GET IT, he sort of did once I explained, but not so much he reacted I guess how I would like him to react. Apparently though, my friend has said that when she sees him at work, talks to him etc he IS really upset, but he's said "I have to be strong for her, I can't just sit at home upset because I physically can't do it I need to just carry on with life, I just don't know what I can do to help her, so I'm giving her room" ER - the LAST thing I want!!!
Anyway, she told me that she had this happen to her a year ago. A few days after her procedure in hospital she was sitting at home, upset and in pain and her oh (much like yours) went out, got SMASHED and came home at four in the morning. They never even really talked about stuff before or after that either and she was livid. Because of what's happened to me, she's felt able to approach him and say "that was selfish, insensitive, WHY?" he said that at the time, he simply could not sit and watch her upset he couldn't put it right, it made him feel useless and whilst he understands now that he prob shouldn't have done it and how horrible it must have been for her, that he didn't mean to hurt her at the time and it was his way of dealing with it...
whilst I REALLY don't want to push aside how obviously hurt and grieving you are - some men are USELESS at all this. My oh, is wondefully sensitive, caring and lovely usually and even I have been shocked at how "cold" he's being - I've actually had to really bite my lip and understand (having been told by friends) that we need to (a little bit) allow them their selfishness and dealing with it to. I really hope that doesn't upset or offend you. Just that, I get where you're coming from and the women on this forum have been a rock in a way that my oh just isn't and, it looks like, cannot be... I think they just don't feel things or deal with things in the same way we do and that can be very very hurtful.
Have you tried telling him how it's making you feel by sitting him down and just saying: look, we need to look out for each other, you've had your drinking to help block it out but I need a bit of help here? I would put money on the fact he GENUINELY had NO IDEA at all (god knows how men work, honestly) that his actions were doing this to you... (not that it's forgiveable, just somewhere to start from perhaps)
If you need to talk, let me know. I've almost had to put all my feelings aside and get on with things because of how 'together' my oh is being and the fact I cannot talk to my family and they feel I should be 'smiling'. I really hope you're ok and sending lots of love xxxxx
and also sorry you are having to go through relationship problems aswell. 
. If it's any consilation my DH and I are greiving at different paces too. He delt with things right away when we found out and I've only just begun to let myself deal. That said... I just want you to remember that everyone deals with loss in different ways. Try to give him some space to deal in his own way, and support him in it, while still being open with each other. If he wasn't a horrible guy before then chances are that he's just carrying on the only way he knows how. I know its tough and it does feel horribly lonely at times, but I promise things will get easier. 
