I have a problem down below, please help, i'm so worried?!

I'm 19 and have never had sex before, but did masturbate often however have stopped now because of what i'm going through its been 2 months. My doctor prescribed me co-amoxiclav because i was having pain in the tube above my right testicle. the pain for that has now gone. however i still have pain in my right testicle, going to the right side of my bladder and inner right thigh. My semen also comes out cold. another thing is when i need to urinate i just feel pain in my bladder and can hold it in for ages if i have to. my doctor has done a urine sample and has found no infection. also i have had a loss of sexual attraction/desire, before all this i was unbelievably horny all the time, however now it is virtually none existent and i find it hard to get an erection. My doctor is no help in this matter, please help me or give me an idea of what it could be. Thank you!!