I slapped the hell out of my daughter. She is already 2 months old but still can't take my full dick.
That doesn't sound right to me. Have you considered what it would feel like to be touched against your will?
I don't think that my daughter could feel pain. Otherwise, she would have cried. I think she enjoyed it.
It doesn't matter what you think your daughter can or cannot feel, engaging in any sort of sexual act with a child is cruel and illegal. As a parent, it is your responsibility to take care of your child and shield them from anything that would cause them harm. If you are caught sexually abusing your child, you are likely to go to jail.