I had a minor surgical procedure, down below at our local government hospital. The head Nurse invited 3 young 1st Year students to watch. They didn't bat an eye. Unlike me.
The last time I traveled (Jan. high season ) there was a long delay to get a bus to Jomtien. The bus company sold tickets to north Pattaya and then mini bused us to our hotels. Price was around B300.
OP best check with the Bus company.
Sounds like an abscess to me. The OP said it was the size of a walnut. I have a Perennial Abscess which flares ever Year or so. Doctor prescribed antibiotics. It bursts after a few days. On 2 occasions I have had minor surgery to remove it.