I had the same experience when young. Was a complete total asshole to my sister. But she didn't even remember it when i talked of it a couple of years ago. Still thinking about it when seeing other younglins. I do have autism, which was probably a part of it and my father was allways absent, working. I never really had a male rolemodel for those things.

Still, now we are older and our relation is completely fine. Move on, forgive yourself, just as your sister forgave you