What Causes Excessive Burping?

I occasionally get burps that seem to need to be forced out and when I burp I sometimes burp up a white tasteless non acidic foam with most of my burps. I also has a slightly tight cramp like pain under the middle of where my ribs end (feels like the pain when your stomach does when it is about to growl from hunger but never does) I do know my stomach produces to much acid but have never been diagnosed with anything. A few years ago I went into the er for severe abdominal pain and was told I had to much acid and within a few days if I hadn t went in my stomach would rip open and bleed all over my appendix and that my appendix would burst and probably kill me.