tonia First of all take a deep breath. You cannot afford to get yourself in such a state, think of yourself first and foremost in all this.
Now, how did you get on with your son before he moved out in the first place? How was he as a teen? How old is he now?
It sounds like, if his wife and baby have gone to live with her mother, that he is kicking back a bit, reverting back to his bachelor life or his life before he moved out and had a family. Especially as he is inbetween jobs right now. Does he not need some space to get his head together and figure out for himself what his next move is? Does he not need some help with doing that and some support.
I know that when my teen kicks off and gets angry it is usually because he is feeling scared, unloved, insecure and his default button is to shout and curse when all he really needs is a hug but because he has hormones raging then he wont ask for a hug, he'll yell and try to get attention that way. At that precise moment I feel like showing him the door too, which is the last thing that my son would want or need. It is hard being a mum to a son who has things going on in their head and won't let anyone in at times. But you just have to hang on in there and hope that they come round. At other times my son can be loving and caring. Is yours like this at any time? Take whatever little bit they give out, making you a cup of tea, anything, it is a good sign.
If this is not the case and your son is just plain awful, then I would seek to having a word with the police because if he is not on the tenancy or deeds then he is trespassing if you have asked him to leave. If you are determined for him to go and know that you cannot live with him for a moment longer, then you have to deal with it now. If you can live with it for the time being, then I would leave him to his own devices in the house. I would sit down and do some ground rules and give him a copy and keep one yourself. Do this when he is calmer and get him to sign both copies and you do the same, both agreeing to what you say. You could add that you will stay off his case for so many weeks to let him get his head together but then he has to commit to finding a place and a job. You could say that he has the use of this or that, whatever but make it attractive to him too so that his temper is calmed down. Think of a child and a temper tantrum. It's the same really. Give him something to be thankful for in return for him keeping the peace more.
With regard to his dad, leave him to it. Think for yourself, do some nice things for yourself. Leave them to it for a bit. It's like a pack thing and the males have just got their alpha back albeit that his dad should be the alpha and he should be towing the line with what he says. But it's not like that, and for some peace just now, lay off both of them, leave them to each other and go and find some space somewhere away from the pair of them and relax a bit. You cannot go on getting so worked up, it is not good for you. It will all blow over in time. Take care of yourself, and stay on here for a vent.