Injury And Ed. Easily with medications?

I am a 19yr old male. About two years ago I had an injury to my testicles. I met a gp and a urologist , also got a normal ultrasound everything turned out to be normal. But I till date suffer from things , example , when I had the injury I noticed that my erections got weaker , after that I cannot have an erection unless and until I physically touch myself. Even then I feel  pain on the bottom left of my penis many times. I never get morning erections. Also I know that testicles are of different sizes but my left testicle had become around approximately half the size of my right testicle. There is many times a sort of numb sensation on the left side of my penis. All of these things are not psychological. I have noticed these things over the period of 2 and a half years. I assume that there is some sort of a nerve or blood flow issue. I am really very worried about these things they have given me anxiety many times. Will I be able to treat them easily with medications? Please help.