chapped butthole !?

I have a monthly panty subscription, I get 3 pairs each month. I’m a size Large. This month I received and decided to wear a new pair yesterday for a family trip to LA. Well I chose a thong. After a 6 1/2 hr ride to L.A. and sitting through a 3 1/2 hour baseball game, we get back to the hotel and my butthole is hurting 🤨 Turns out they sent me size medium and I had on a small thong all day! Now my butthole is so tender and irritated, in the shower I noticed it’s a little swollen!? Is there a product I can use to help it become less irritated ☹️ helppppp