Your absolutley right uknowme, get some legal advice and contact Womens Aid and some of the other recommendations further down the thread. I am sure they will help you and give advice on what the next steps are. I would not tell h anything at the mo, play your cards close to your chest, try and get your finances organised if poss and tell your family.
I know this advice may seem easier said than done, but you will feel better once you start taking control, even if it is behind the scenes.
Please you must do what is right for you and your children, am so upset for you this must be the hardest thing to cope with.
Keep posting, we will all support you for as long as you need.