Is OTHER wrong in the post ? POST : This is going to be a long one, so please grab a snack and get ready.

Before I go into detail, I want to tell you some background information. A few months ago my brother (we'll call him B) was diagnosed with level 3 ASD. For those of you who don't know, level 3 is the most severe, but each case is different. 

He's also completely non-verbal, along with having a condition known as Pica. Pica is a condition in which someone will try and eat non-edible objects such as paper, rocks, etc. B will try to chew/eat anything he can get into his mouth, at times its been so bad that he's coughed up a small paper ball from tiny scraps of paper. He also has incredible strength for his age and little to no fear of pain. This combination leads to a daredevil of a toddler. This of course means he pretty much needs constant supervision and attention. 

The thing is however, watching him isn't really the problem. Watching my siblings is something I've done for years (albeit not by choice) so it really isn't a problem for me. I love my parents dearly, and I know they love me too, but I'm getting to my breaking point. Everytime I come home, I'm either watching B or getting my 6yo sister off of the bus while my mom takes a nap with B. There's been times where they've pulled me out of school early to watch him. Every time I ask if someone else can watch him I get the spiel:

"We don't trust anyone else with him" "we can't afford a babysitter like that" "they won't change him enough (he has very sensitive skin, sitting in a dirty diaper for more than a few minutes will result in a rash)" 

I understand that they're worried about other people watching them, but why can't they? They always find a reason to leave me with him, and my dad in particular is the worst with this. If he has plans, he will ALWAYS leave early and come home late. A week ago my dad came home 2 hours late without telling me at all. Neither of them are good at communication, so whenever I call them 9/10 they won't answer. I'm worried for the day that there's an emergency and they don't respond. 

I've tried to explain this to them, and how it makes me feel used, but each time I'm essentially told that it's my "familial duty" to help them and that the reason I babysit so much is because they're working so they can feed me. That it's normal for people my age and in my circumstance to do what I do. At times it feels like they're trying to guilt trip me over them having to fo their jobs as parents, and like I'm some burden. They both had horrible childhoods, and I truly believe that they think that their parenting is normal.

Good news however, is that I convinced them to pay me to do it, however I do not get payed Every time I babysit, and when I am payed, it's typically not much.

AITA for feeling this way? Am I being selfish here like they say or do you think it's not my responsibility? There's much more I can say, but I maxed out the character limit, so feel free to ask for more information.
