I have tapered down to 7mg of Valium, but i think that the trazodone.. Can I...

From 30mg of Valium throughout the whole day I have tapered down to 7mg at night and I have been taking 50mg of trazodone, together with it, all of the time. Since I broke my arm in August 2012 I have gone from 5mg of Valium back up to 7mg because I couldn't sleep. However, I have an awful dry mouth and very bad taste problems, so much so that tissue paper would taste better in all the food I eat and it gets worse every day. I have read of the Trazodone side affects and they point to the mouth problems that I have and relate to many other of my physical problems.

Can I continue to stay at 7mg of Valium and come off of Trazodone first? If so, how much Trazodone should I taper of at a time and how long should I stay stay on each step?