Is it unreasonable to ask for an alternative to public school in my situation?

I have PTSD from being abused by my father, and school has many triggers(? Tumblr ruined that word) like yelling terrifies me, sometimes touching terrifies me, and I m constantly nervous around people. It doesn t help that I have no friends because I can t really connect to people because I m wary of them. It gets progressively worse every year. Am I selfish to ask my mom if I can finish high school a different way so I can focus on myself, recovery, and my education because in school I dissociate and am to nervous to pay attention. I think it will be a benefit to my education and mental health but I feel like a failure and ***** for asking.