I think I had your 11th grade. I can see see the lines of roofs out the window of my math class where I spent my time instead on in the class.

Maybe start from the "future" and work backwards? Assuming you'll get to 26, what would you like/imagine your life to be like then? Figure out how to get some of that? Do you have any interests at all; music, fantasy (great for writing) any classes you do better or worst in? I was good in history and English and now, at 56, I'll be getting a BA in history this May. I messed up my first attempt at college. But I've made it to 56 and now wouldn't have changed anything. It was uncomfortable, painful, and very hard at parts but it is "life"and I'm making it through. Other people do it, we can too.