(((nightowl))) Please listen to your T. Maybe in the future you will be able to "let" him back.. but for some reasons, your T says it isn't in your best interest right now. Why isn't he helping with the bills? The children are still loved by him, shouldn't he be helping, if he means to? Why would allowing him back change your financial situation, if he isn't helping now? Is the house also in his name, yet he doesn't care? If he really understands, why wouldn't he take care of these things for you? If he isn't able, why would he be able if he lived with you? You don't have to answer... just wanted to jog your thinking, if you aren't.
Living "on one's own" is tough. I find it still easier than living with someone who only lived for himself.