I had similar problem & my support group put the blame on the Cymbalta.
Some people say Wellbutrin has less sexual side effects.
This can happen with any antidepressant. Or not. Just depends on the person. Only thing I can recommend is if you decide you don't want to stay on this drug, stop it sooner rather than later -- it's a very difficult one to stop taking when you've been on it a while. As for this feeling, it could pass or it could last. I think you having the desire is a good thing, many people lose that as well, but difficulty enjoying the act is one of the most common antidepressant side effects.