left testical very painful when aroused. lump on the back of it

[satch11]

I have been experiencing pain in my left testical for about a week. a few days ago, it got so bad, I could barely walk. Yesterday I noticed that the back of my testical had a painful lump on the back of it. last year, I had a vasectomy. At that time (a few weeks after my vasectomy) I experienced simular pain and I also had a swollen lump in the same place as I do now. It went a way though, and it didn't seem to affect my sex life. A week ago when I started feeling the pain my wife and I were really sexually active, a lot more than normal. On top of that I was also masterbating. That's when I started feeling the pain, and then it just got progressively worse. So I decided to stop for a while. Now, I notice this swollen lump on the back side of my left testical. It's really sensitive and, today, the first day in a week I desided to do anything sexually, I started feelling deep pain when I felt like I was about to have an orgasm which I never did. So I've made an appointment with a doctor for monday, but I'm so terrified that it might be testicular cancer that I've been searching the internet for answers, when I stumbled upon this site. Any helpful advice would be appreciated. Thank you
Ryan

[Scott]

It's more likely to be an infection than cancer, but seeing the doctor is the right thing to do in any case. Good luck!