For anyone who may stumble upon this with similar concerns, while my doctor didn't explain why this happened, she instructed me to use 1% OTC hydrocortisone cream twice a day and cover it with moisturizer, cleared up in a few days.
Can you get into a Planned Parenthood or an urgent treatment center? If they say it's herpes (which it doesn't sound like since it's lasted so long, but a lot of docs like to visually diagnose herpes and are incorrect), make them culture it with a type specific culture before accepting that diagnosis. They should also do a wound culture to see if there is any bacterial infection.
When you pee, you can use a water bottle that squirts and squirt water over the area, which will help dilute the acid in the urine (which is what causes the stinging), or get some latex gloves, and cover the area with your hand.
Good luck!
Well, I'd look at this as similar to what happens after child birth. That does really sting! What they had me do is alternate between tucks pads that I'd leave in my underwear and prep H on the area, also a sitz bath and a spray bottle after urinating. You fill it with warm tap water and spray when you go. Definitely helps with stinging. The other things aid in healing. feel your pain . . . that's rough! Hope it heals soon.