I'm ashamed that my brother was overlooked because of my autism

I have both low support needs autism and a younger brother. Unluckily for me, my autism, coupled with the fact that I was a homebody and a couch potato until my early teens, and that I went to magnet school and therefore had no walking distance friends to roam my suburb with, makes me pretty immature. I resent that and as I am nearing adulthood, wish to remedy the fact.

I was, unfortunately, also a coddled kid. For example, I was driven to magnet school while my younger brother would have to take the bus; I always offered, both to him and to my parents, to come up with an alternate arrangement but my brother claimed he was okay with the bus. Until I outgrew my behavioural issues, a lot of time was spent on that. My brother fell by the wayside and had to grow up more quickly, despite my parents' best efforts and their being loving rather than neglectful, until I outgrew my behavioural issues years and years ago, and was able to learn to navigate transportation.

In my early teens, I also spent little time with him. He always used to ask me to play video games with him, but I was all too eager to leave. Eventually, he stopped asking, and when I invite him on walks with the family dog, I get my just deserts as I am rightfully rebuffed most of the time. When our parents encouraged us to write short stories one summer day when we were young, I was in a bad mood and took it out on his story, which was about another video game and was pretty good, especially since he was a kid when he wrote it. He crumpled it up and I feel remorseful and ashamed years later. At least for this, I have a plan. I'm going to tell him that I actually thought the story was good and that he should write something else if he ever feels like doing so, even though it's been several years (I just want to get it off of my chest).

My brother is now a recluse. I infer he thinks that we don't want to spend any time with him and that he isn't worth it, and my parents are rebuffed when they try to spend time with him now. This isn't up to me as a sister, but when I try to talk to my parents about this they tell me not to worry because it was all years ago and now he refuses to spend time with us anyway. But I'm convinced that, as loving as my parents were, we rebuffed him first. They do their best especially now that I am older, but I want to atone for my once having been so immature and needy and taking away from him. He should not have had to be so mature because of me! There has got to be something I can do to be a better sister and show him that we all love him. I cannot go to my parents as they would tell me to let go of the shame and not to worry anymore as it was years ago. (While he still plays video games, he wouldn't want to play them with me as I am completely new to video games and would be bad and inexperienced; he also has friends he plays with.)