God, Hollie! Don't give in to him if you can help it. It is NOT your fault, don't let him think he's cowed you into submission.
Can social services take his kids into care if you get an injunction?? To be honest, if his son's being violent and abusive then you need to tell the police that. He's not your problem, so don't feel guilty about doing it. if they arrest him then it's his own fault. i'd get an injunction on the pair of them. Can anyone stay with you, like your daughter and her hubby?
When I left my ex, it was because he tried to strangle me and hit me. I managed to get in another room and I called the police on my mobile. They were there in 10 minutes.
They got me out, and they told him to stay away or else he'd be arrested. He denied it, said he'd never touched me. The police could see the marks on me though.
If he lays a finger on you or threatens you so you believe you will be hurt, that is grounds to arrest someone these days, believe me. Pushing, shoving, screaming in your face, spitting, preventing you physically from leaving a room etc is ALL assault and arrestable.
All I can suggest is something like keeping everything - phone, keys, money, passport etc. in your handbag, and if he starts then grab it, and get out of the house. You can call the cops once you're outside. They will get you back in and get him out. Just make sure you take your keys, as you have to prove you have rightful entry etc.
Don't let him see your bag, just put it near the door etc.
My ex used to lock the doors and hide the keys so I couldn't get out to get help. He held me hostage upstairs once and neighbours rang police after I screamed for help, but he made me say I was fine to make them go away. I had no choice.
Believe me, people like that back down when there's witnesses. Once you have support and he knows people know what he's done, then he's finished - he won't have the power over you.
Also, if he hits you, you have every right to defend yourself. Just make sure you can get away from him and out of the house if you retaliate, as some men will lay into you even more for "standing up for yourself".
Just think it through eg - if he starts in the lounge, walk out to the kitchen/hall etc.. Don't let him trap you in a room with less than 2 escape routes.
If you ring Womens aid, someone can come and be with you or help you over the phone. Keep the no. of an emergency solicitor handy - see yellow pages, if you need an injunction quickly.