Many different meds can cause sexual side effects like loss of desire. There are also medical conditions that can cause such things. It can be embarrassing to bring up a sexual problem with your doctor, but it shouldn't be. Sex is a normal part of life and many at some point in life deal with a sexual problem of some sort. Unfortunately many are too embarrassed to talk about it so they just deal with it when it could be something easily treatable. If not your psychologist, perhaps talk to your family doctor?

As far as asexuality, check out Asexuality.org. There are many views about it. I pondered it once myself.