I know that you have replied to my topics on this same subject, so now it's my turn... I have a similar situation as yours. Sometimes my stomach gets bloated and I get nauseous then start to feel panicky, other times it's the opposite with anxiety/panic starting and then the stomach problems. Since I posted about this the last time, I've been trying to just accept that it is just anxiety and not let myself get worked up over it...for the most part, my stomach has been better, a couple of days when I let it bother me and it got much worse. With the symptoms I have, bloating, slight nausea and sometimes the feeling like my stomach is in a vise, and nothing else, I'm starting to worry a little (stress little) less. I figure if it was something serious that it would have gotten worse by now or I'd have other symptoms showing up, and it wouldn't come and go the way it does. Mine will be gone for weeks and then when something stressful happens, it's back. This has been going on for over 6 months now, so if something were really wrong, I think I'd know by now. I've been told that the stomach is very sensitive to stress, so it makes sense that it would respond to our getting anxious.
I understand your frustration over this, I'm right there with you...there are days that these stomach issues drive me crazy. Even though I can, at times, be very rational about it, it can still cause me major anxiety. Hang in there, and I really hope you'll feel better very soon!