Harry/James
You're entitled to that opinion, and you're entitled to not feel the attachment. You wouldn't be the first. Lily, before, mentioned that Andromeda wasn't as accepting of her daughter. Though that may be different now from my understanding. The point is, just because someone is your blood, doesn't mean there's an automatic bond between you when you meet.
And just as you're entitled to your feelings, so is he. They may intersect in some places, they may not. But you're both coming from vastly different backgrounds.
When you're ready, if you're ready, you'll do what you decide is best. Until then, he'll be taken care of. Whether he likes it or not.