I'm glad to hear you survived the Endoscopy your Gastroenterologist did on you. Being anxious about it isn't unusual. I had to be knocked out. It's good they didn't find anything. No ulcer, no acid reflux, no major health issue. But I know you're frustrated about walking away with no answers.
Have you ever had a full blown anxiety/panic attack? It's scarey and painful. It's like having a massive heart attack! So if your doctor is recommending you try some relaxation techniques, maybe you should give them a try. Stress and tension can bring on all kinds of problems in us. And any health problems we already have are only made worse by them. If removing some of the stressful things in your life doesn't help with your symptoms, see your doctor again. Tell him you tried what he recommended and the symptoms are still there. We may not always agree with our doctors but sometimes we need to try what they recommend so we can rule out that possibility. Keep us posted on how you're doing. We'll help in any way we can.