[Lawtan]

I don't think you failed. Honestly, to this outsider, it sounds like there were other things (definitely outside of your responsibility and control) that led to your father distancing himself. He may have been fully honest when he said he didn't care as much. He may not understand it himself. Sometimes, people (parents included) are like that. Perhaps he still needs some "growing up" of his own to do.

Perhaps, as an example, my father will never be "enough" for my grandfather to care about him beyond calculated gifts. And yet, he has started a small Engineering Risk-assessment company in 1994 that supports ~10 families. He has pushed himself into a position where he regularly supports local military veterans (of which, my grandfather is one), etc. In order to please his father, my father has pushed our family to the point that my mother has threatened divorce multiple times due to stress. And yet, any time they come over, it is to nitpick.

This is not to say that you should "give up" on your father or family, but to illustrate that you can't force/change how your father (or anyone else, for that matter) feels.

One thing I am trying to learn myself that Espy sort of taught me is to take what opportunity you can to make your life better. In this case, perhaps talk more with your mother and sister?

*Offers 1001 hugs*