What could cause numbness in the genital area and anus?

Hello doctor,

I am a 28-year-old single male and a labor worker. It has been about three months now that my genital area and anus area got numb. It all started when I got back from work with a pinching sensation under my left scrotum when I sat down on the floor. I went to sleep that night thinking it was nothing, but the next day when I went to work, I noticed this strange sensation like it was burning. I thought it was some rash from my clothes, but when I reached home, I noticed that I could not feel the left side of my penis and scrotum. I went to the doctor and explained, but he said it was just a fungus skin infection and prescribed me some anti-fungus cream, but it did not help with the burning. He also tested me for STD and sugar levels, but everything was normal. I even got my prostatectomy checked, and it was normal. That night I went to the restroom to masturbate, and when I was about to ejaculate, I flexed my pelvic muscles. I felt this pinch sensation under my right scrotum. That was when my penis, scrotum, and anus lost sensation. When I walk, it feels a stinging and burning sensation. I feel like I am wearing really tight undergarments, and my penis sometimes aches. When I sit down, it feels as if I am ejaculating mostly on the left side. My doctor also checked my testosterone and cholesterol levels. The testosterone came back a little low, but my cholesterol came back high. I doubt this could be the cause of my problem. It all happens really fast, and I also feel gassy. I would like to know if I pinched a nerve. How can I treat this? Will I recover from this?

Please help.