Hi,
I think what you're doing is a good thing. School will always be there. People may not understand what you're going through because you look fine physically and that is apart of the illness. You can't worry about what others think even if it's your parents. I guess you will have to try to educate them on your disease. You have to take time out for yourself to try and correct these problems as if you don't they will just get worse. If you are suffering from the stress of school and work etc. this will run your endocrine system down more. You need to rest.
I had to finally go on disability in 1995 as I could barely function.
I have a good quote for you:
"Your Health Is Your Most Valuable Possession. With It You Have Everything. Without It You Have Nothing. Don't Leave It To Chance." -Unknown
If you don't have your health you don't have ANYTHING.