I have taken dozens of different types of anti-depressants in the last 18 years and only two did not give me any sexual side effects. Remeron and Welbutrin.
Only two problems with them. Remeron WILL absolutly make you gain weight. It makes Paxil look like a diet pill. Remeron works ok, but in the long term I found it not to be as effective as I had hoped.
As for Welbutrin. Some people say that with Welbutrin alone that they have eliminated their depression and anxiety. I personnaly see Welbutrine as more of an add on drug to a more effective antidepressant.
Welbutrin alone was not effective enough for me even at high dosages. I guess it depends a lot of just how severe your depression is and exactly what type of depression you have.
Many of the mood stabilizer class of medications do not have sexual side effects, but if you need an antidepressant too then the choice can be a tough one.
In some cases if you do start on an SSRI or SNRI antidepressant and do have sexual side effects, they can lessen in time, but this takes a while.
You're right, valium doesn't work long term, nor is it meant to. I would get a referral from your family regarding treatment and a proper diagnosis. From there, the specialist can figure out what meds will work best. Some meds don't affect your libido, but if your anxious and/or depressed, you don't have a libido anyways. I take meds in the Mood stabilizer class, but I was fully screened before meds were prescribed. It's in your best interest to see a psychiatrist.