I almost asked this on the welcome post, (I'm not sure where your from or what your options are) but pertaining to the school situation, does your school offer a "home bound" program? It's a program mine had where ill students could come in a couple days a week after normal school hours & be taught by one teacher for a few hours-the remaining work was done at home & brought in next time to that teacher. I had no idea there was such a thing when my counselor arranged it so I could finish out my senior year & graduate. I'm not sure if all school systems have this in practice, but it may be worth a shot in finding out!
And being young only makes this disease harder-I couldn't fathom the things you've faced and over come since the age of 9. But you can look at it this way, you my dear are a warrior. From what you've only said above-you have fought & dealt with things many adults haven't or couldn't imagine. We all have our battles, our own flaws and our own insecurities-but if we love ourselves and recognize that inner strength that keeps pushing us onward despite the circumstances we are facing, then you ought to know how able, beautiful & fierce-some you really are. And although some days you may feel like you are the lupus, or thats what you think anyone might see, know that you are you & no matter how life changes, no matter how many curves lupus or anything else may throw your way-being you, on the inside, most of all, makes you pretty darn amazing. A book is only as awesome as the meaning behind the words on its pages.