How do I go about finding what's wrong with me?

I honestly can't keep functioning like this! About every two weeks or so, I get extreme intestinal discomfort, sulfur burps, gas, and diarrhea and the discomfort is almost always only alleviated when I throw up. This has been going on now for about a year and the time between the episodes is continuously getting shorter. I suppose I'm just starting to get desperate; I have no idea if any of you know anything about it. I am hoping to see a gastroenterologist sometime soon but I've been to one before