Not experienced, but this is what I've accumulated:
-L-Glutamine (10-20,000 mg per day, start lower and increase, you'll get stomach pain if you take too much) can help heal the gut. I don't know if it would have any immediate effect, but if you've got damage, this could help.
-Try something like grapefruit seed extract? It's doubtful you have Candidiasis after the way you've been eating, but if there's some kind of overgrowth or gut dysbiosis, that might help regulate (excess/pathogenic) bacteria levels so your fermented foods can actually have an effect.
-Get your doctor to accept a stool sample to test for bacteria levels. Maybe you have something else going on. This should give them/you a decent starting point to see if your gut bacteria is okay or not, even if it doesn't show all of it (you'd have to biopsy to see more). They might not be able to tell you how to treat it, unless you see a naturopath, but lab results are generally helpful.