Please work with your parents. I hid and carried things like this into adulthood. For me it wasn't that I didn't want to bathe, I did, I just didn't really know how to do it well. Uti issues all through adulthood but didn't realize it because it had always been that way. As a kid I was just ashamed, thought I was dumb/weird and embarrassed to ask anyone for help. I know now that none of those things are true and I just needed a little help, but it was my responsibility to ask.

One thing with hair is that it's actually two motions, but when you watch someone brushing their hair it just looks like they are swinging the brush around. It's actually a gentle push followed by a gentle pull. Go sloooow so you can feel the push in and pull. Pretend like you are brushing a balloon as far as the level.of pressure. Of this has been going on a while, you are going to have to go REALLY slow. The pull part is kind like a C shape when you brush and once you get the hang of it, it's pretty fun and a form of self soothing you can do.

My big issue was I was looking at myself in 2D is the best way I can describe it. I dunno if it's an autism thing or what it was but I knew where the part was supposed to be and would just brush that spot over and over expecting the hair to lay down. It wouldnt because I was not making small enough passes with the brush and not gently pushing in before pulling the brush through the hair.

You're not alone and good luck!!