djufo is describing a varicocele ( a varcose vein in the testicle, usually on the left but can be either) That can give you a heavy feeling/ dull ache in the testes, and yes a it can make you sterile if on both sides. I think that the change in semen cosistancy is from the lack of LH to stimulate the testes, im not sure of the control mechanism for seminal fluid but it may have some relation to the low LH too. You probably have sust flu like described and have this common occurence of decreased ejaculatory volume from supraphysiologic doses of testosterone