Quite a few people with candida and/or heavy metal problems suffer from strange heartbeats. I suggest you consider the possibility that your thyroid is giving you trouble.
I had thyroid trouble before (chelating with ALA was removing Iodine from my body in addition to mercury). I started taking a little iodized salt every day and my thyroid problem went away. I'm not sure if that will help you, but I suggest you check into thyroid-related problems and see if that helps you find a path forward.
If your thyroid is the culprit, please consider that the problem (and the likely yeast problem in your mouth) may be caused by something else (like heavy metals, for example).