Chronic unresolved digestive issues. ANY ideas appreciated!!!

In late December 2010 I somehow caught a parasite (cryptosproridum parvum). I had nausea, diarrhea, heartburn, bloating, gas, general indigestion and excessive hunger. I was treated with 2 rounds of Alinia and retested after that. The parasite was gone but I still have lingering symptoms. I still had pretty much every symptom except the diarrhea. Some of the symptoms started to decrease a little after a month (specifically the hearburn, bloating). However, the rest of the symptoms remained up to present day. As of today I have a lot less heartburn, and less excessive hunger but I'm still nauseous with an upset stomach every single day.

I have had an upper endoscopy, colonoscopy, HIDA scan, abdominal ultrasound, pelvic exams, celiac disease blood test, probably more I'm spacing on at the moment. All my test turned up negative for anything relevant. There were slight erosions found in my terminal ileum which 2 GI doctors said seemed inconsequential and unlikely to have been causing my symptoms.

I'm at my wits end. I'm miserable every single day and I'm giving up. I don't know what else to do or what else to try.

Side note: I'm lactose intolerant so its not that.