OP, the only reason not to leave him (yet) is that he would have unsupervised care of the children for part of the time. This is unthinkable, given the way he behaved towards your 8 year old. Unfortunately the only way you can ensure that your children are ok is not to leave him (yet).
What you can do is 'grey rock' him. You don't want to be married to him (who would?) But this isn't the right moment to leave him. So you have to check out of your marriage mentally. It's just you and the children, only he's physically there as well. But nothing he says can hurt you - you ignore and walk away if he starts insulting you. You don't have sex with him, because who would want to be touched by anyone who can hurt their child? I don't think that he sexually assaulted you (though how did he "make" you touch his dick? That might put it in a different light).
The business about having to say his name to ensure that he's listening is pure shit. Don't do it. If you speak to him and he "doesn't hear because you didn't make sure he was listening", shrug and say it's not your problem if he isn't paying attention and you are not repeating yourself. Just say it matter-of-factly, not in an argumentative/upset way. Then walk away.
If he acts like a shit, take the children out - go for a walk, to the park, whatever. Play a game with them - whatever they're into. No bad-mouthing, no drama.
You will be able to leave him when the DC are old enough to choose whether they want to spend time with him. You can in the meantime start to plan your escape. See a solicitor and find out what you would be entitled to in the event of a divorce. I don't know how you organise your finances, but if you don't want him to find out that you've paid a solicitor, keep back a bit of cash every time you go to the cash machine, until you've stashed away enough to pay for an hour (will be in the region of £300 - some will give you a free hour, but that depends where you are - you'd need to ring round to find out).
I think it's sometimes frightening to read on here about contacting Women's Aid, or living in a refuge, or claiming benefits and so on. The idea of having to do any of those things scared me almost as much as the idea of leaving my ex husband. I was afraid of having no house, no job (SAHM), no money, etc, etc, etc, but didn't want to become a "single mum on benefits" (for want of a better way to put it - apologies). In the event, I didn't have to do any of those things; being married (as opposed to living together) cushioned me enough to be reasonably comfortable. It was still terrifying at first - I had never had a utility bill in my own name in my entire life - but it's fine. I love the freedom now, and there is no way a man is coming along and spoiling it.