What brand of Valium?
I was prescribed some late last year that had no effect whatsoever on me, and I've never had that problem before.
I posted the brand here and got back several replies from people having had a bad experience with that particular brand...can't remember the name now. (btw, benzos are not only addictive, they also impair memory ).
Anyhoo, I told my doctor and she prescribed a different brand and everything worked out...hope it does for you also.