Don't forget to look in to the less obvious culprit... Overtraining. I had the same issue a few months back and it was from overtraining. I didn't even notice I was doing it till I had multiple symptoms add up and I crashed. First I got lethargic. At first just a little and then slowly it got worse and worse till all I wanted to do was sleep. No libido, none, 0, absolutly nothing! (Same as you, only I had 1 naked chick, my wife, on top of me and I had to fake it big time). Haha. I thought to myself, "Never would I have thought!". I was also very irritable, and I could not sleep very well. The soreness in my body that would usually go away in a few days was not going away. Any of this sound familiar?
The hardest thing for me was forcing myself to take a break! It is a mental thing. You don't want to backslide on your training, bur looking back on it that is exactly what I was doing to myself while training. I just took a week off from training, kept my nutrition in check, and got as much sleep as possible and all is good now.
If this is bot the problem and does not sound remotely correct, I appologize for taking up this much space in your thread! Hope it all works out for you!
Oh.... Wait... Almost fogott, it may be one more thing. You might be turning into a homosexual!