It seems to me that you are attempting to create, what has been till now, a non-existent reality. Spent some years, during my childhood, in hospitals. Being around people who nurse you, take care of you, provide for you is just not enough. It has had a life long effect on me.
Your situation is different, in that you had someone abuse you, while your dad stood by, and did nothing.
So let’s go with something, that for me is real.
At our essence, we are just a bundle of conscious energy, encased in a temporary form. This also applies to the rest of the universe, but for now that need not be addressed.
Going to see and be with someone who there is not the rapport one wants is not easy. Still if you attempt to give of your self, in any manner, you are likely to receive some sort of a response. Build on that. Take it slow, assume you have all the time in the universe to do so.
Going as slow as you must and as fast as you can, while not getting ahead of your self.
Nothing is easy and this fits that. All you can do is do your best and know that you tried.
The result is not in your control.