My GP was more than useless so I can relate to you on that one.
I found my way to my current doctor by accident actually. Back when I was really bad I was struggling to move my bowels and despite having done a few enemas at home, I wanted to have a colonic
done professionally so I could be sure I was doing everything correctly myself. I googled for a clinic and as it transpired the main doctor working at the place I attended turned out to be a private heavy metal toxicologist doing a lot of work with mercury toxic patients and children with autism.
Given that Hg and candida go hand in hand there was no convincing necessary. Intact I had a few labs done that showed no candida. My doctor insisted that it must be there and of course he was right. I'm very great full to have his assistance.
If you're looking for a practitioner, why not try mercolas tip and visit a mercury dentist and ask them who's the best person to see re metals and candida? Or even ask around at your local health food stores etc?
I hope you have some success!