Can I tell you how bad your situation is OP? I do not mean to make things harder for you but you need to understand how this situation strikes someone who is just reading about it.
Every so often, there are threads on the Relationships board that show people to be living in abusive situations that are so horrible to read about that they truly sicken me and make me lose faith in human nature, and so I retreat from Mumsnet for a bit, or play around on the lighter pages, like Baby Names.
Then I tell myself come on, Daemon, you feel this sick just reading about it, what more the poor souls who have to live it, and what more their poor children?
Your thread was one of the ones that I read and was so sickened by a few weeks ago that I had to take a break from the Relationships board. That is how bad your situation is to an outsider, it really does not bear reading about.
You work, you have your own money, with a bit of juggling, you can find a caregiver for your children who will care for them, while you work. There is no reason at all that you are allowing this man to do this to you and to your children -- do I understand correctly that you have not 1 or 2 or even 3 but 5 children with this man? That is 5 human beings whose self-esteem, sense of worth and confidence in themselves and in their future relationships is being damaged by watching this dreadful model of a relationship play out.
I know you are exhausted, and it is easier just to give in, but please make this the final straw. Please get out for your children. Please don't come back one month from now to report something else that he has done to make your life harder. Please make this the last time this happens. I am sorry for the endless missive, but I really wish good luck and much strength to you and your children.