I think interference with libido and sexual function by exogenous androgens is much more common than people think, even if not as dramatic as in your case. This was driven home to me by recent experiments in which a difference of 0.3 mg in the daily dose of testosterone made a very large difference. I couldn't even believe this result until I repeated it. The circumstances are unique, so I'm certainly not suggesting that the average guy on TRT would be so sensitive to minuscule changes. But I think it supports the general principle of using exogenous androgens judiciously.