What Causes Tenderness And Sensitivity In Testicles?

I m 27 years old. Three years ago I contracted Chlamydia and was cured in time. However, a year later (two years ago) my testicals felt soft and not sensitive to touch anymore (feels dull). Now I m still experiencing the problem. Last year I went to two doctors they say my testicals looks fine and the scrotum look fine. Also, to add to the concern, my primary doctor said I have high cholesterol. For 3 to 4 years ago, I barely go to sleep at night so get proper rest that I need. Basically, I want to know what maybe the leading cause for my testicals be the way they are now?