Sharp, burning pain inside tip of penis when urinating

Hi, I’m going to try make this easier to understand: Sex: Male Age: 20 I’ve had sex only with my girl, and she has only been with me (100%) I have a sharp and burning pain on the tip of my penis when I urinate. It’s a little red and also hurts if I just touch it. I also have very dry light red spots all over my body (mostly legs) and sometimes they itch, I have had this for about 4 months and it hasn’t really bothered me but maybe this has caused the pain, I’m not sure. I can send pictures of this if need be. I would be so grateful if somebody could help me! Maybe some antibiotics, but I don’t know which antibiotics! I really want to get rid of this by the new year! If you need any more information I will tell you. Thankyou! Rich