Struggling with Graves Disease in High School

I'm a Senior in high school and I'm having a difficult time right now balancing things. I've always been an A student, but with graves I've gotten Bs and even a C or 2 in my classes and I hate it. I can't find the energy or motivation to get up and complete my assignments, or even my chores at home. My teachers think I am just making up excuses and often ignore my 504 plan, as if they've never even heard of it. I feel like having Graves Disease is lowering my worth, and I hate it... especially since my perfectionist in me feels I am letting myself and everyone around me down all the time. Does anyone else ever feel this way?