Diagnosed a month ago, pls give me advice. How do I use this steroid? - My story and other questions

Kinda tmi but I want to be detailed to receive the best advice. So sadly this started with a little cut down there, then itchiness, and all of a sudden the entire labia on that side started turning hard. I thought it was like a scab under the scanner first that I just couldn’t see, and then it became white, I thought o damaged skin, and then whiteness spread, and then the hardness spread until my entire area was completely that. I’m not going to lie I don’t look down there frequently, so it advanced slowly for a couple months without notice. There’s some fusion (I think that’s the word).

I was looking up what this could be and the only thing i was coming across is LS. After looking at a couple photos, I knew. So I kind of self diagnosed before I even went to the doctor, which I know you’re not supposed to do, but they did confirm it. That was a hard pill to swallow because I knew, but in the back of my head I was hoping I was wrong. My doctor also was not really educated on it at all. She said she could diagnose it, but I didn’t really get any advice when it came to how to apply my steroid or when to stop or how to avoid the bad side effects. I’ve been using the steroid maybe about four or three weeks now twice a day and the past three days I just started using it once a day.

I don’t know about sex affecting it because I haven’t had it yet, would that cause a LS “breakout” in the lower area? Can you get this on the lips too? I know pretty much nothing about this disease