I have a friend who's son (no, really) was taking Vyvanse. He experienced severe dry mouth, hand-wringing, decrease affect, and a very short fuse. Hope you get this resolved; I'm sure you feel miserable. I believe that my friend's son began taking Metadate with more success. Still not sure of any contraindications with Xanax, though.
I am sorry you feel bad it sounds like the Meds, best to go back to the Doctor and ask about them and if they are interacting with each other.