Of course the major bad news would be a STD, which could include a virus that may decease after awhile with treatment. And to make your day even worse, cancer of the gonads, which a guy on my old high school football team has (only 35 years old). His started like yours, sensitive nuts. The greater odds are that the junk that passes as a "designer pro-hormone/roid like" could be the cause. The possibilities would increase if it was put together in China, Mexico or India for example. Though even bad batches are produced in the U.S.. Guy's who just take the money and run after selling bad stuff.
Sometimes a nerve, where the spine/ lower back and hips are not inline, can cause the "boy's" to hurt. Chiropractor or deep sport massage may help. In any event, why waste time on this site asking questions. Make a doctors appointment today. Time may not be on your side if something serious develops. Good Luck.
