Make that four...I had candida, have fibro--but not so bad anymore. I have *some* thyroid symptoms, but not enough to make a diagnoses (I do have diabetes, tho). Jess, the candida die-off can make you feel pretty crappy too, but nothing measureable by the docs.
Do you know your blood type? It may be something you're eating. You may not necessarily be 'allergic', but may be 'sensitive' according to your blood type.