What Should I Do For The Burning Sensation On The Skin Between Thighs While Urinating?

I'm a teenage girl and I don't have my period, I haven't had sex, and I haven't masterbated. I have this burning down there whenever pressure is applied and whenever I pee. I tried sitz baths and various creams yet nothing worked in the long run. It always came back. I'm using Balneol and it gives me temporary comfort but it always comes back the next day. I don't understand. The doctor has tried all he could think of and nothing has helped. Is there anything I can do? I've found that when I separate my legs when I pee I don't feel that burn so it must be something with the skin and I know it's on the inside, not the outside.