Persistent Rash Under The Penis. No Relief With Hydrocortisone Cream. Solution?

So recently (bought a week) ive gained a friction burn on the bottom underside of my penis near my testicals....even though i knew i shouldn t i masturbated. and then shaved my pubic area with a WAHL automatic razor (like the ones for your head) i then knicked my self...it was small but it hurt a little. but the rash kinda persisted then was getting more irritated. as i couldn t take the irritation ne more i recently got hydrocortizone cream and when i put it on it burned like crazy i was in SEVERE discomfort....and then when i woke up i did it again cuz while sleeping it got irritated again it burned and later cooled, then i wasn t haveing a problem for a while. but im afraid to continue using it seeing as i still have a slight opened burn wound. i tried baby powder but as doing research i am getting worried that this will b persistant please tell me what can i do to fix this,,,,its uncomfortable. and by the way i know this is not a transmitted disease. so again can you please tell me what i can do to resolve this issue?