Testicular decease. Please suggest.

I have a little pain, burn and discomfort in my right scrotum and testis at the same time what i saw that excessive looseness in my right scrotum and testis and in addition to that my right testis is circling around into the scrotum and unable to understand testis upper part or below part and I even confused that whether the testis are on there place properly or not. It seems to me that some kind of skin or layer of my testicular has affected or disappeared. Note:- 1. I'm facing this problem from last 20-24 months 2.i had consulted with a urologist and he has given some medicines. Till the medicine over it was some relief in pain, burning and discomfort. 3.pain, burning and discomfort increases with every nightfall or masturbation and right testis tucked up. 4.i had gone for ultrasound of testis and the report was negative. Do I need to go for MRI of testis or any other test. Please suggest.