I'm gonna come off in a blunt way with this one. First, to answer your question, yes, you are clearly nuts. Your situation has proven that you can't remain faithful to your husband (or ex-husband), your new bf, your kids, and worst of all, to yourself. There is no right or wrong answer or an easy solution to this. I actually feel bad for your ex-husband for having to go through all this because of you. This has really been going on for nine years? I guess I gotta at least give you credit for being able to go through with what you have for that long. Also, it sounds to me like you're using this new bf as a rebound but maybe you two have something going on that I can't see from your post.
Alright, to start off, take the children out of the equation for now. Focus on what YOU really want. The way I see it, I don't think you and your ex will get back together but that may have to do with the fact that I haven't seen marriages work a second time if it didn't work out on the first try. If this new bf seems right for you and he likes you the way you are, maybe it's time to move on to this different man. But again, this will depend on what it is that you think is right for you and only you know the answer to that question.
I'm not sure how old your kids are and how long you've been going out with this new bf but from your post, I can tell your kids matter to you a lot so ask them what they want, that's if they're old enough to understand what the concept of love, breakup and all that stuff. Whatever it is that you decide on, just remember not to look back otherwise you're just going to end up having regrets.