Pain that radiates to the testicle can also be related to conditions outside of the testicle such as a hernia, or even spine disease. The fact that you are also having pain with urination, may imply that you have urethritis or possibly prostatitis as a cause of your discomfort. Orchalgia, chronic testicular discomfort can also be the cause of your discomfort. The thickening of the semen that you are referring to has to do with the viscosity of your semen. Various factors can affect this such as your overall state of hydration. Excessive viscosity of the semen can be associated with infertility. An evaluation with a urologist would help to clarify some of these issues for you.