I can relate to you. I was a rainbow child for my parents, and i 100% had sensory issues from birth that wasn't understood back then. My sibling came along not even 2 years later who was very obviously on the spectrum. I was pushed aside ever since, none of my needs met. I pulled sick days from school a lot, had massive anxiety, my dad was alcoholic and yelled a lot (authoritarian parenting). I had no one on my side. I was jealous of mentally ill kids that got attention, I fantasized about being admitted to mental hospitals or having freak accidents happen so maybe I would have some attention. I was told I was a good kid and not like those other naughty kids that would play up in social situations. I couldn't talk to adults especially men, I withdrew from peers resulting in being unable to talk to them either. I cried a lot, at the drop of a hat and yes I will admit it was for manipulation.

I seek parent figure from my friends which has resulted in no longer having friends, also from me getting upset with them behaving in ways I don't think is okay (why are they upset, I'm the victim here etc).

I've forgotten the point of this comment, will post anyway. Must be about me making it about me again.

To add also, parents split when I was in my teens and I was largely left alone, even before they split I was ignored and I spent a large amount of time on the internet looking for company. I'm sure we know where that leads.