Lack of motivation to do anything

So I recently have been doing VERY poorly in school. I have started just not turning in assignments when I know they are due and know how to do them. I am extremely smart and I know I am but recently I have just gotten so sick and tired of constantly doing work that I already know.

I have ADHD and had the doctor up my dose to see if it would help, but after two dose changes, I still have no motivation.

My family is as concerned as I am and have offered to pay for any academic support I need, but I just know it won't help.

Feel free to ask for further details.

Thanks,
-Anonymous-