After reading all your info, im leaning more towards parasites. The pains dont happen often enough to write them down. I believe they happen every 2 months or sometimes longer. And I have had the pains on an empty before too.
But whats weird is, my dad seems to have the same problem. I used to be heavier in weight then him, and now I am about the same weight as him because I am losing weight. When I had these pains years ago, I was still happy as can be and was pretty healthy. So why would having these pains still today, but my health is awdful now. I have constipation, hair loss, dry flaky skin on face, depresssion and many more.