You deserve to be with someone who truly loves you and accepts that being a mother is an important part of who you are. This person may never come to love your children as much as you do, but he should care about them and understand it is critical that your children can always count on both of you to be there for them if he is going to be your partner in life. This guy may not be mature enough to deal with beng a father figure to your children even if he loves you - not everyone can handle parenthood, even when it comes to their own children. Only time will tell for sure with this man, but he doesn't sound ready.
If he's not the right one the sooner you know, the better.
My husband and I both have children from previous marriages. I think sometimes the fact that we each had to deal with children that were not our own made it easier than if one of us had been childless as we could look at each conflict from both sides.