Being with someone who already had a child

When I met my fiancé he already had a child. I always told myself I would never be with anyone who already had a child but I guess I was wrong. Is it just me or is it har le being with someone with a child. First like the criticism you get from family and friends like omg why would you be with someone who al had a kid? Then the baby momma drama like why are bm’s so bitter like why? And I say that because I would get if you were an ex wife but you were just a baby momma like he didn’t end up committing to you, he left even if you guy shared a child so why be so bitter and try to get under my skin saying you and your child will always come first than me and mines and all this other non sense? Does that really make you feel better? Also my fiancé since he only see his child on the weekend when they are over he makes our kids feel like that child is a bit more superior because “they are not here all the time” is that valid? I always tell him it’s not our kids fault that his first child isn’t always with us? Am I the only one who goes through this. Am I being too sensitive or is this normal. I knew it was going to be hard to be with someone who already had kids but omg that’s an understatement 🥴