Could my symptoms be a direct result of anxiety/stress?

Your symptoms include:
- indigestion
- acid reflux type symptoms (specifically, what are these symptoms you are experiencing?)
- burning in my mouth and chest after eating
- discomfort travels to my back (between my shoulder blades)
- spells of belching
- worse during day

These symptoms are different than the "Burning Mouth Syndrome" that you are concerned about, as your description seems to be concentrated primarily in your "gut" (indigestion, belching, back/chest pain):
- chronic burning pain in your mouth. The pain from burning mouth syndrome may affect your tongue, gums, lips, inside of your cheeks, roof of your mouth, or widespread areas of your whole mouth

So, let's start back at square one with just looking at your symptoms and not finding a diagnosis at this point, as it sounds like you have all of the information you need.

You are experiencing these unpleasant and distressing symptoms, and have had the necessary tests conducted to rule out a medical condition associated with your gall bladder and liver. That's great that you were proactive!

It sounds like you did have some slight acid reflux signs show up on your tests, as well as your previous extreme stress and a stressful episode this year. There are quite a few options that you have:
1. Psychological distress concern: you stated that the anti-depressants are working, but not enough. Since you are considering that these symptoms may be a direct result of stress/anxiety, have you also considered following-up on this instinct to meet with a Psychologist or other Mental Health Provider? Anti-depressants alone may not be enough, and stress, anxiety, depression...these are all very powerful medical conditions that can produce the physical symptoms you are reporting.
2. Physical concern of Acid Reflux: Since this was found to be slight in your case, I am wondering if the symptoms are being compounded with your stress and anxiety, where the medical test may show it as "slight", but you are feeling the symptoms as very painful and distressing. If this is the case, you may want to follow-up with your doctor about possible acid reflux remedies (here is some information/tips on preventing/lessening acid reflux: Mayo Clinic: Acid Reflux, GERD, Heartburn, and additionally follow-up with a mental health provider to treat your anxiety.

Acid Reflux and Anxiety are often conditions that occur simultaneously, so your doctor may be on the right path. You can read more about this at EmpowHER's page: Acid Reflux and Anxiety Attacks

Please let us know if you need any assistance in finding a credible Psychologist!