I still don't know what my problem is either. I had a couple of really anxious days and then I started having heartburn and nausea every day, basically after everything I ate.
My doctor put me on prilosec and then nexium. The heartburn has gone away for the most part, but the nausea remains (or is worse) and I am burping after everything I eat and drink, sometimes even on an empty stomach. I'm waiting for results for an H. Pylori test, which is what your doctor would probably test you for if he thinks it is an ulcer. I'm kind of scared too, but mostly just frustrated.
Keep in mind that if you have an ulcer or gerd, it is manageable. Not pleasant, but there are much worse things to have. Sorry you're going through this as well, and it sounds like yours is anxiety related too.