This is the start of a variety of fairly unpleasant symptoms which seem to affect some people worse than others, get ready for levels of mouth pain and sore that are tough to ignore. Certain mouth washes can ease the discomfort usually after stinging like buggery on 1st application. stay away from a lot of over the counter ones that say mild they burn the mouth. I had to dilute one called difflam but it was a life safer, then I eased back as I was doing it too much. Luke warm water to rinse acid out of mouth often in the day helps.
Building up a little routine and sticking to it. Salt and bicarbonated soda much milder than the teaspoon to half a pint often quoted helps. Read past posts on this site, and be strong for your hubby it is a rough road but the light at the end is that its keeping you good for the long term.