Sorry you find yourself in this situation. You may not realise it but you have taken the first important step. You have realised your husband is abusive and that you are being abused.
Your children are witness to this abuse all day every day, you cannot protect them from an abusive relationship unless you extract yourself from it.
Why do you think your dh is abusive? IMO because growing up he was subjected or witnessed the very same behaviour that he displays with you at home.
It's highly likely that your children will end up in an abusive relationship, either being the abuser or being abused.
It is important to realise that staying for the children is therefore not promoting their welfare into adulthood. They may well be fine in most respects but it will be when they start to develop relationships of their own that their early years/life starts to cause them problems.
The relationship model they have at the moment isn't healthy. Neither was yours, hence your predicament at the moment.
Another day with him is another day wasted. If I was you I would use the time from now onwards to build a career for yourself, getting yourself financially secure so that one day you can set yourself free. Of course you don't need money but it helps a lot.
Your dh doesn't want you to have money or friends because they are some of the greatest luxuries in the world aren't they? Providing freedom and joy. Now he can't be letting you have too much of that can he?
To anyone reading this who have dc in an abusive relationship: Yes they do see it: it all goes in: he isn't a great father : he's abusive and your dc have a strong chance of being so too if they remain in abusive environments.
Your DH might live your DC I'm not saying he doesn't but it's a funny kind of love when your perception of it was so distorted in childhood that you terrorise future partners.
OP I see there's a big gap in your dc, was he worried that you were becoming too I dependant with just a seven year old?
Does he do the nice and nasty cycle with you?