Haven't had one for ages but currently have 4 (!!!)
One on either side of my tongue, one on my inner bottom lip and one right on the back of my throat. Initially thought I was getting a sore throat then looked with my torch and saw a very angry red ulcer.
The pain is bad enough but it's how generally unwell they make me feel that really sucks. My head is killing, all the time. I'm taking paracetamol throughout the day and it's barely touching it. I feel drained and my glands are up.
I'm using mouthwash and salt water gargles but I know from experience that nothing really helps, it's just a waiting game. Anyone else?