Has anyone else ever had stomach numbness with an ulcer or GERD?

Let me start by giving a small history.  About a month ago, I had an upper GI for stomach pain and acid reflux and it came back that I had moderate GERD, esophagitis, and maybe the possibility of a duodenal ulcer lower down.  I was put on prevacid 15mg once a day and then later to 30mg once a day.  In the night a couple of times I've woken up after laying on my left side and it felt like my stomach, the organ itself was numb.  This may have been just a sensation or it may be because of ribs pushing on it or anything else I suppose.  Since it was the night and I was laying on that side, I just figured it could fall asleep like any other part of the body.  Yesterday, the stomach numbness occurred during the day while I was just sitting around the house, and I decided to take a nap, but woke up and it was still there a couple of hours later.  It went away after that but I have just had bad nausea since then and the area hurts a little bit.  My worry is that somehow the bloodflow was cut off and my stomach's going to die.  I'm wondering if anyone else had experienced this sensation, or could shed some light on why it might happen, or if it's related to GERD or ulcers.  Thanks.