Get on the Beroccas! Or even better, Holland and Barrett do a supplement called "Busy B" which has a ridiculous amount of vitamin B in it (something like 20,000x your daily minimum of B12). That and corsodyl knock off sorts me out. I think there's actually a mouth ulcer thread on here?
Interesting. I get ulcers a lot (seem to get them more when I’m stressed. Which is always at the moment!).