I just have to say I hope you find the strength to change the locks and not let him back in...that is a decision you have to make but it really is the best one.
Take a break from him and I can bet you will realize in that break that you deserve better, so do your children. I know it is a hard step to take when you are in the middle of the chaos but it is well worth the step! It is the hardest part but it is the one thing that will bring you peace and happiness.