Candy, I know it is hard, but you CAN do it, you CAN stay strong. You have been so strong already. We are all proud of you.
Yes the children are stressed and hurting now, but it is NOTHING compared to the stress and hurt that would have been caused had you continued to let him treat you the way he has done. You are doing the right thing, they will thank you later (child of divorce talking here ) Please try not to drag them into discussions and decision making etc - you can explain to them later, but decisions like this are hard enough for us to make, it is too much to expect from your children to be able to process it. However it's done now - move on, don't involve them in any more discussions and forgive yourself for this temporary upset in their lives, because I promise you, it will be worth it when you look back in a year's time, maybe even sooner. And remember that the best thing you can do in their interests now is keep strong and stick to arrangements, going back on anything is just dragging it all out, because this is all inevitable, it has to happen some time.
Remember you are not responsible for him any more, and most importantly, you are NOT responsible for his emotional wellbeing. If he ends up on the streets (it is very very unlikely that he will, BTW, whatever he tells you) - it is NOT your problem. I know it sounds hard but you simply can't afford him the emotional resources. You are stretched to breaking point dealing with your own and the kids' as it is. Don't allow him to bring you down.
You are so close - so close to getting a new life for you and your DCs. Focus on that life, free from money worries, free from worrying about him, what he is doing, where he is, free from fear. You deserve that life, and it is waiting for you. Hold on. We are all rooting for you! (((((Big hugs)))))