I'm sorta stuck and dont know what to do for my future? (details inside)?

Practice makes perfect. Do a lot of math problems, become the math problem. Math trains your brain so you don't do something dumb in the future, it trains your brain so you do something amazing in the future - so you make the right decisions. I was picked on too, except I enrolled in martial arts when I was around 7th grade and by the time I was a sopre in high school I was a 2nd degree black belt. If anyone picks on me I just leave them alone because I know for a fact I am better than them. I have amazing grades for a reason, it is because I practiced and studied. What you have is a chain reaction, being fat led you to have anxiety and do bad in school. Now that your thin, go to school and be amazing.