It looks like you're going to have me crying all day! I still worry if my younger two were damaged by the chaos they grew up in.
All three of my children were born in less than three years, with the younger two being only 11 months apart. It's the oldest who has autism.
My kids didn't never had hard and fast rules or chores because my autistic son was impervious to any sort of carrot-and-stick parenting strategy (we now know that he's on the Pathological Demand Avoidance profile of the autism spectrum, which explains EVERYTHING.)
Meltdowns were constant. One day still sticks out to me: My 3yo daughter had had an argument with her best friend, and she was in my arms sobbing her heart out. But then I heard my son banging his head into the bathtub upstairs, so I had to peel her off of body to go stop him. I still think of that as my "worst mom" moment, leaving her crying by herself so I could go keep her brother from hurting himself.
When the younger two were in their tween years, they became increasingly resentful of the disparity in discipline and started to question why their brother got away with everything. Finally, I told them that I would make their brother follow the rules, but here's what it would look like: constant screaming matches, no peaceful evenings, not inviting friends over because they'd never know what it was going to be like, etc. And, feeling a little resentful about having to defend my choices to my kids, I told them (truthfully) that ever single choice I made about disciplining their brother was made with their best interests as much of a priority as his. And that not trying to enforce certain rules on him assured them a better quality of life.
Sometimes I think it must have been like growing up with alcoholic parents, not ever knowing what things were going to be like when you get home.
Now they're in their freshman and sophomore years, and they're doing just fine. They're still a little embarrassed of their brother sometimes --- the meltdowns are gone, but it's obvious that he's not your "typical" teen. And I get that. I tell them it's OK to feel that way, but it's not OK to act on those feelings.
And all of that rambling brings us to where we are now..three weeks from high school graduation and still uncertain as to what comes after that.