Canker sores

For years I've had canker sores (mouth ulcers) off and on, never really found the cause. Apparently super common with autoimmune conditions. Right now I have 5 total and they're killing me, has anyone found any hacks to reduce the frequency of them? Or the discomfort? I already take b12 which is supposed to help, hydrate a ton, and try to be pretty consistent w dental care. It seems like a never ending situation. I realize in the grand scheme of things it's not the worst, but I'm having trouble eating and drinking and frankly, it's annoying! Haha