Step parents

Am I the only one that feels this way? Step parents go through so much sometimes especially if the mother/father of the kids on the other side is difficult. I don't have kids with my bf and I can't help but sometimes feel left out or the odd ball. I get so much shit from people about dating a man with kids. Apperantly it's okay for a man to date a woman with kids but not the other way around. I feel sometimes I'm a nobody even though the kids adore me . I bust my ass to make sure they have everything they need whether it's food or clothes. We spend quality time together playing dress up, making pizzas, playing outside everything kids enjoy. The babymama and I never got along due to issues of her own. It was never me, after awhile I did act on the situation due to I'm tired of letting things slide. We can only take so much as people. I don't know what she thinks is going on but for some old reason she thinks I want her kids when that's not the case. Me and my boyfriend are trying for our own child. We are adding to the family even though she says we are not a family. But we are, I've been around for awhile they are comfortable around me they refer me as their stepmom and I never even said that around them. I am not a rude person, I am not going to leave them just because of her "feelings" she expect me to have my own kids and drop hers? I wouldn't feel right doing that and the kids would be so hurt. I hate it sometimes but I don't regret being in the kids lives. I hate that my bf is in the middle of all this all he wants to do is take care of his kids no matter what the circumstance is. Sometimes I want to just give up but that's exactly what she wants me to do .