I think it's important to bring everything up with the doctor that way he will be able to pick the right meds for you. If your sex drive is down it may be due to one of the meds you are on and he can make the appropriate changes.
I read you last post and know that you are nervous. My daughter's pdoc basically spent most of his time gathering a history and some do psychological testing which are answereing lots of questions. The improtant thing is to answer them as honestly as you can that way the doctor will be able to per scribe the proper meds and recommend the best treatment.
I think it's great that you are going to a Bipolar specialist rather than your GP. I am sure that you will be evaluated much more thoroughly.
I hope everything goes well and be sure to let us all know how everything goes.
~ Goody