Wounded is right. Ask yourself if you want to be with your ex for the rest of your life, because your kids shouldn't have to go thru this ever again. The reasons you broke up should be taken into consideration too - and perhaps counseling would be a good idea!!
You may be contemplating this because of several reasons -- familiarity; the kids; fear of entering into a new relationship and getting rejected; safety; security; convenience, etc. You notice I didn't put "love" in there because you don't even know if you're in love with him. That's something YOU are going to have to figure out. Obviously you feel something for him since you get jealous when he sees others. And just because your heart doesn't go "pitter-patter" when he comes into a room doesn't mean you don't love him or that you're not IN love with him. When people have been together for a length of time, love goes deeper than that, and the 'pitter-patter' stage is gone, but the love is still there and very very deep. YOU are the only one who knows if that's the kind of love you have or not.
I wish you the very best. I hope whatever you do, your kids come FIRST in your decision. They are the ones who will get hurt if you make the wrong decision. Kids are ALWAYS the ones who get hurt first in these cases, so don't make them go thru any more trauma. God bless and please take care. Hugs, Lee