Since it seems like you are already doing it, why not go ahead and start living a separate life from your children's father? Set up your own household (whether by moving out or moving him out) and start living your life the way you want.

If you want a relationship, this action would free you up to find a decent, attentive man who will treat you right.

Your children could still regularly see their dad.

If finances is the issue, please think long and hard about that. Finances are the one thing it is easier to improve when you weigh the pros and cons of a relationship. Yes, I know living costs are expensive, but it is easier to spend less or to earn more than it is to get a partner to keep promises he or she does not want to keep.

I imagine if you suggest separate lives to your children's dad he will say "oh, no that isn't what I want" and it probably isn't. He wants to have his cake and eat it too. But you are in control of whether you want to continue to enable him in this. Courage!