Has anything happened with his work or family lately? There may be issues there causing him to be distracted and not able to relax? Have you tried talking to him? Does he understand your frustrations?
I can tell you from experience that Zoloft has the potential to make you forget you even have a penis. Maybe he could lessen the dose? There are also other anti-depressants out there which may not have the same side effects.
I understand your frustrations! I've been getting rejected from the other side lately. It seems like I have to wait for all the planets and stars to line up for her to be in the mood!