The condition of your tongue often coincides with the condition of your health, so I feel it means that you are unhealthy. A regular doctor’s office can determine if you have thrush, but they likely will prescribe antibiotics which are ineffective for fungal infections.
One way to determine whether you have candida overgrowth or not is to try out the diet, with antifungals, and see if you experience “die off.” If you have die-off, then you likely have candida overgrowth. If you experience no die off but an improvement of your symptoms, you might have only a slight overgrowth or flora imbalance.
Parasites is something else I would recommend checking out because the symptoms of parasites overgrowth is very similar to candida overgrowth.