Internal burns?

6 months ago I was drunk and I did a bad thing. I took a light and did a fire fart. I have done it a couple of times before but this time I just felt that something was wrong. Something wasn't right with my penis, it felt and still feels like I have less sensation in my penis. I promised myself to seek up a doctor the next morning but instead I called a "medical information" here in my country, and they told me to seek up a doctor if it contiues or get worse. The first time I wanked after that and when I got orgasm, I almost didn't feel anything, and the seamen that came out looked like small water drips, and I can tell you I have never seen seamen like that before. Now It comes seamen but sometimes it doesnt look normal, like it used to and the sensation is still not the same.

My theory is that I maybe have burnt nervs, muscles or something in anus that affects the sensation in penis?
The light I used have a little bit bigger flame than normal lights (dont know if it matters).

Im so angry that I did it and this isn't an easy thing to talk about, my friends just laughs when Im telling them. But I just know that something isn't right with my penis.