Don't worry it seems now that it may not be esophageal since you can scrape it off.
The brain fog indicates that the candida may have gotten into your bloodstream so i still emphasize on consulting an stomach/intestinal doctor since finding out the cause is prio no.1.
Candida may be caused by celiac disease, hemochromatosis, low zinc levels, diabetes type 1 & 2, bad diet high on refined sugars, Antibiotics , mercury in the body, sensitive intestinal linings (sensitive stomach) etc.. so addressing the disease at this "early" stage would be a little difficult.