Right, stop messing about and get your arse into gear. You've been downtrodden too long.
Work out the financial situation, get evidence (there's a thread telling you what you need, somewhere, maybe someone will link) of income and assets.
Decide where and how you are going to live. Make two plans, one for 'with children', one for 'without children'. I would normally assume that children stay with mother but yours have learned how to abuse you from their father (previous thread) and they go on holiday with him and without you (previous thread - from memory..).
Write down all the things that are wrong in your marriage and why you want a divorce. Take that with you when you see a solicitor. Go for divorce right away, no 'legal separation' nonsense.
When you know exactly where you stand, and have plans, raise it with your husband. Don't accept any 'I'll change' stories. If he tries to be violent remind him that you will now prosecute him for anything he does.
Lastly, when its all underway, talk to your children. Tell them that after a decade sleeping on the floor, you can't live like this any more, your health is failing (previous thread again). If you can provide a home for them, offer them the opportunity to come with you. If not, or if they don't want to, tell them they will always be welcome to visit.
If you spend the rest of your life alone in a bedsit, sleeping in a bed and having peace of mind, it will be better than what you have now.