Ditto with Nursegirl. Suppressing acid production long-term produces a rebound effect, because the stomach must produce acid to digest protein and minerals. So it produces more and more and you suppress more and more. The above advice not to lay down soon after eating is a very good one, but your symptoms could be a lot of things. Remember, all these names -- gastritis, GERD, etc. are usually digestive in nature, so solving the digestive problem gets rid of the problem instead of continually medicating it. There are gentle natural remedies that help with the symptoms, such as aloe vera juice, DGL, or just taking a good full spectrum digestive enzyme supplement. These don't work by suppressing anything, so they don't cause the rebound effect. There also might be something you're eating that's causing the problem, or it might not be from digestion at all. See if you can work this out. Good luck.
There are some kinds of symptoms where doctors are more likely to have a knee jerk reaction and throw certain medications at a patient. GI issues/ "GERD" is one of the biggest ones on the list. I definitely am wary of that kind of "fast track" treatment, for a lot of reasons.
There ARE people that absolutely have GERD or other GI issues, but I personally feel that before prescribing these acid reducing medications, more thorough assessments should be done. Minimal symptomatic treatment for a very short term period is one thing, but I don't agree with an ER doctor prescribing a GERD type medication with little to no follow up.
Long term use of the "GERD" type meds can actually cause a lot more problems than one started out with. Just be cautious about an ER giving you a new GI regimen based on one assessment of symptoms that really could be attributed to MANY things. It's true that some chest pains can have a GI related cause, but I think docs are way too quick to just jump on the GERD train rather than referring the patient to a GI specialist, or doing more in depth diagnostic studies.
As for your anxiety, do you have a history of anxiety? Do you feel anxious, do you worry a lot? Can you give us a little background on the anxiety aspect of yourself?
Your case sounds identical to mine. I found myself going to the ER 4 times this year for the exact same thing and I am someone who never goes to the ER. 8 weeks ago my family doctor put me on Pantoprazole (a proton pump inhibitor), which is used to treat Acid Reflux/GERD, gastritits or other GI issues. He also put me on a very small dose of Lexapro (which I fought hard), but I have to say it's been getting better. I still have the pain at times in my upper left chest area. Look at a diagram of the human anatomy and see if it's the same general area...that's where the stomach actually lies in your body. I would have a burning sensation that would cause me to be short of breath and panic. I can't recall it being triggered by anything and didn't know how to handle it. You might want to talk to your doctor about possibly trying a PPI. It's an acid supressor and a little stronger then Zantac or Pepcid or follow up with a GI doctor. Good luck!
You said that you focus on the pain and your breathing. Try your best not to focus on it. Take deep breaths if needed. If it is acid reflux stay away from foods that cause it, especially right before you go to bed. Do you have anxiety?