I agree with Jane ^^ above.
And to reiterate, PEOPLE DO NOT PUNCH THEIR DOGS IN THE FACE AND KNOCK THEM OUT! Sorry I had to yell that.
Your dog is a product of what YOU made him, from the way he acted, it doesn't sound like this is the first time you have yelled, punched/hit him.
I also think, as jane said, you need to step back and analyze how you treat your dog. Maybe he'd be better off in a different home with someone who has more knowledge on how to treat animals.
I agree with that.
It's confusing to our dogs when we act one way when sober, and another when drunk. Irratic and undependable which is unstable for a dog. So they will already be on edge if that's the situation in the house.
Using aggression (punching your dog in the fact and knocking him down) to prevent aggression (growling and nipping) does NOT work/teach/train. It only ADDS to the confusion, irratic situation and STRESS for the dog. So instead of stopping the problem it pretty much assures it will not only happen again, but escalate.
Not cause of the dogs behavior. But because of YOUR behavior and not teaching.
Don't mess with your dogs food. Put it down and let him eat. If you want to start TEACHING then (whenyou are sober) use tricks and training with food rewards FROM YOUR HAND to teach him your hands are good, not threatening any they GIVE food rather than take it away (or punch).
As is mentioned, a good Alpha Pack Leader isn't good cause of force. They are good cause they are dependable, reliable, consistant and FAIR. Good leaders don't do so with force and fear, but with using good sense (sober sense).