Honey you need to get out ANYWAY, to make a point if nothing else.
There is a thread here somewhere - It's happened again - read it.
he slapped her, she didn't react as best she might have done, and he has now hit her again.
This guy got drunk - perhaps to even deliberately give himself permission to kick off at you, so he could blame the drink and let himself off the hook.
I would say that you need to get out, and not go back until he has addressed and admitted his issues, apologised and been genuinely remorseful, and been sober for a good long time, so that you can try to regain trust.
My fear is that any time he wants to kick off and have a pop at you, he'll have a skin full, come home and beat the crap out of the house, and then eventually YOU.
You need to nip this in the bud now, by cracking down on it in a total and comprehensive way. state that you have a zero tolerance to that behaviour and that IF you decide to carry on with him, that if he ever, and you mean EVER does that again that you will call the police and have him removed. permanently.
At the moment you tell him that you need space and time to consider your next options as you are not prepared to live with a violent drunk and it may be that you leave or he does, but that is how serious it is RIGHT NOW.
By stating your massive intent this early on, you may be able to stop any further re-occurrence.
You need to remind yourself though that this IS a one shot situation. Any more drink fuelled aggression and he is history, and he'll be seeing his child through a contact centre.
You are only married 2 years. This nasty situation out of the blue worries me greatly.
Is there any other aspect of his behaviour that has upset you, worried you, frightened you over the time you have been together? Is he supportive of you, helpful, involved in your family?