Is it wrong to love your children only because they’re the children of someone you love? For example, if you had kids with an ex-wife you didn’t love as much, and you feel like you wouldn’t love those children the same way because you don’t love your ex—would that be wrong?
Your feelings are what they are and you can’t change them, only accept them as they are and try to understand them.
You can control your actions, and treating your kids differently because of your feelings around their other parent would be wrong, but you can’t help how you feel.