Intolerance to spice. Here? any ideas?

I've been experiencing progressively worsening intolerance to spicy foods since the past 2 months. Having even mildly spicy foods causes severe burning in my tongue and throat and stomach upsets. It has gotten so bad that I've to completely abstain from even the mildest hint of spice. All this started off around 4 months back, I had a very bad episode of indigestion following which I developed loose stools (lasted for almost 2 wks), which never really resolved fully. Ever since then I developed alternating bowel habits (occasional loose stools alternating with  constipation and  normal stools). Around the same time, I also started having recurrent ulcers on the sides of my tongue. There is also a kind of weird taste in my mouth along with dryness of mouth, bloating, loss of appetite and occasional nausea. Weight loss of about 6 kgs in these 4 months' time. What is exactly happening here? Any ideas?