After years of symptoms, frustration, dietary restrictions and self-diagnosis, it turns out that I've been suffering from anxiety/depression all this time. All those physical symptoms (ALL OF THEM) were a consequence of insufficient neurotransmitters in my body. I'm now taking an anti-anxiety/depression medication and pretty much every symptom has gone. I can eat whatever I want, whenever I want and I don't suffer for it.
I'm embarassed that I put my friends and family through one fad diet after another when all I needed was a once a day pill. I wish I had figured this out much sooner. Not only would I have saved everyone (and myself) a whole lot of inconvenience and distress, but I would have saved a fortune on shonky remedies and naturopaths.
Dwelling on it is pointless. I'm glad that I'm well, or at least on the road to being well. I accept that pride and stubborness prevented me from accepting anxiety as the cause for a long time. I accept it now.