I've suffered from this in the past. For me, I find it seems to happen when I tend to get dehydrated. I find drinking lots of water helps them heal faster as well as the cool water feeling good on them. I gargle with Listerine as well when I feel one coming on. I have 1/2 cup of probiotic (or whatever it's called) yogurt every day and don't feel this adds to or helps (but it's good in other ways). They are a nuisance for sure so I feel for ya.
