Dad forcing me to act "normal"
I'm NT and I love giving and receiving affection. My daughter has autism and when I hug her sometimes she looks off and keeps her arms straight down. I always have to prompt her to wrap her arms around me. When I don't get a hug from her it makes me feel like she doesn't care to give me affection. I asked her the other day if she would like me to continue hugging her before I drop her off kindergarten and she said YES!! She loves hugs, but doesn't know how to do it in a normal way.
Maybe that's how your dad feels? Maybe he feels you don't care cuz' you're not hugging. Try to tell him that you care about him then tell him if you prefer hugs or not.
Good luck and btw he loves you, he's just worried about you and wants to protect you.