Why doesn't any stimulants work for me?

I have 3 sleeping disorders and my doctor has put me on Provigal, Ritalin, double the dosage of that, dexroamphetamine, and now adderall. and none of it works. stimulants have Absolutely no effect on me. The 30mg adderall he gave me, I probably shouldn't have but I took 2 of them, just to see if it did anything, and still nothing. I'm at the end of my rope here and ready to just give up. I'm so tired of being tired all the time. Has anyone ever heard of anyone else have the same problem. I'm just wondering if there's a medical reason why stimulant won't work for me. My hand as well as my doctors hands are kind of tyed as far as what he can do cause I have no insurance. On a side note, I take a Percocet, and I can't sleep and am up cleaning my whole house. So it does what the stimulants are supposed to do. I'm basically *** backward! someone help please!!!!!!!!!! Thanks Dawn