Here is why the spit test is not to be trusted:
If you want the best diagnosis, I would try out the candia5 test which is pretty cheap test you can take at home and is one of the best diagnosistic tests you can take out there.
The toxins that the yeast produces and other foods in your current diet is contributing negatively to the health of your brain and this is why you suddenly have anxiety. If you were to supplement with fatty acids such as SF722, flax oil with lignens, coconut oil, PS-100, etc. then this should improve your general brain health. Your brain is largely composed of fat and to heal it you need fatty acids.
I definitely recommend diagnosis before doing the diet because this is a long term battle for most people, encompassing 6-18+ months of doing a strict diet plus a long list of supplements that typically cost a few hundred dollars per month. If you treat yourself without a good plan, you could feel way worse or damage your liver and other vital organs that will have to be healed at a separate time. Additionally, you might not even have yeast overgrowth and could have something similar such as SIBO (small bacterial overgrowth), h.pylori, parasites, strept, mono, and/or other gut bacteria that have overgrown. A lot of the symptoms for all of these digestive related problems are quite similar and there is a whole gamut of illnesses that have many of the candida symptoms.