What Causes Penis Burning With Itching?

hi im 19 years old, i had a bump in my urethra close to the tip of the head of my penis it hurt for a little bit and then i used a swab and hydrogen peroxide to heal it, it went away. A couple days later my penis started to feel lioke it itched on the inside of the urethra and after i had a drink i went pee and it started to feel like it was burning...i payed no attention thinking it'd go away, and then when i woke up the next day i noticed that it was dripping and i had yellow stains in my underwear from it and it continues....whats going on??