Glad to hear it. There's a simple rule: Spend time with people who consistently make you feel good, and stay away from those who hurt you, even if it's inconsistent.
Remember too that you should be one of the people who make you feel good. Start doing stuff today for yourself that you would want a partner to do. Special little treats. Doesn't have to cost, if that's a concern. Be your own loving partner. Baths with candles and a glass of wine, making time for your own favourite creative thing, maybe getting some new equipment for it... reading a book you've always wanted to, learning about something you'd love to be an expert on.
Every chance you get. If somebody treats you like this (even if it's you), you start to get a feeling of what really being loved feels like. It doesn't involve feeling bad because of a niggle from the past, it doesn't involve being pursued to the point of harassment, it doesn't involve risk. It just feels really, really nice, and once you know the 'really really nice' feeling, you'll refuse to let anybody take it away from you by treating you badly. That's called self respect.
If you think about it, even the feelings he's causing in you right now, whilst he's claiming to be a changed man, aren't good, are they? People who are going happily through their day without a care in the world don't post on forums about their relationships. He's worrying you, just by offering himself to you. You're not even in a relationship with him and you're distressed. Avoid him, and anybody else who makes you feel confused.
There are two parts of you; one surface part who thinks it would be great to be with him now that he's changed, and another part, which, if you examine the feeling, is far more visceral. You'll have a physical response to it. The feeling that goes with the 'Oh, shit shit shit, I don't think I should, it feels like it might all go wrong, oh, crap, what about the kids, they need their father but what if he goes back to how he was...' etc If you can recognise that feeling, Bob's your uncle. Memorise it. Avoid anybody who triggers that feeling. It's the feeling that made you post here.
You will never feel that feeling in a healthy relationship. It is your responsibility to steer clear of that feeling. For you, and for your kids.