It is severe heartburn. I had that a few months ago and it sucked!!! Does it feel like it hurts the most on the left side right under you left breast? I had never had heartburn before so I had no idea what the hell was going on. I went to the doctor and they told me to take prilosec otc.My doctor thinks it was due to stres, because whenever I get overstressed I get very sick. After a couple days I was fine, but it was one of the most painful things I had felt in a long time. I also took pepto and tums as well. They say not to take all of that together, but I was in such horrible pain I was doing everything to get better. And to top it all of it was over Thanksgiving, so I didn't get to eat any thanksgiving dinner. I had to sit there and watch everyone eat all that glorious food. I hope this helps. Feel better soon!!!