I am assuming this your first baby right?
I had a tough situation develop when I was pregnant that culiminated with my partner leaving when my baby was 3 months old. It was not drink related, he met someone else when I was 8 months pregnant.
But my advice to you...
The next six months with your baby will be tough.
Babies are hard work (very worth it though) and the lack of sleep, massive change to your life, the emotions you feel for this tiny bundle of love are unbelievable.
Just focus on you and the baby.
Not him.
You and the baby are the most important.
Not him.
Take any offer of help - it's not a sign of weakness or that your not coping. But if someone offers to walk your baby in the pram so you can sleep - snatch their hand off!!!!!!!!!
Keep close to your family and friends. Join mum and baby groups too if you can. You need other new mums round you so that you can share how you all feel, be company for each other, help each other out.
The problems you have with him need to be put on ice at the moment.
There is no point making massive descions now.
You need to have your safe nest for you and your baby.
If that safe nest is threatend by him or you still see no change, then make your choices and do what you need to do.
What I would also say is, from my experience, if things are truly broken, don't waste time trying to fix them.
If you go when your child is younger, they witness less and know less.
And please, please lean on your family, embrace them, let them build relationships as grandparents, aunties and uncles.
Please pm me any time and I send you lots and lots of love and care.
Being a mum is the best thing you will ever, ever do. Your going to be great!!!
xxxx