welcome. glad you are here but sorry for the circumstances.
you commented that you wanted to "fix the marriage" - i'd challenge that - it's only been two years, he has lost a series of jobs and thus does not contribute in any way to the family unit, his alcoholism is out of control and he is violent.
what is left for you to do? get yourself and your son away , safely. you can't fix him, you only provide a handy target....and a roof over his head, food in his belly and yes, alcohol.