Did you stop/start medications after your fundo? Which ones?
I have noticed that starting (I haven't tried to stop yet) PPIs caused a white tongue coating for me. I think it has to do with the ability of fungus/bacteria to grow when there is a change in the acidity of the environment. When I started PPIs, the acid dropped and the fungus was able to grow. Went away in a few days. When stopping PPIs or when having surgery I can see how the same thing could happen.
By the way, relax. Your name on here is "worrisome" and it can be a self fulfilling prophecy after a while. Try distracting yourself with a book, a movie etc, rather than trying to figure out something that doesn't need to, or can't be figured out.