Abdominal discomfort, bloating and acid reflux

On June 22nd, 2024 I was diagnosed with PMR and was started on 20 mg prednisone. By July 5th I was down to 12.5 and had a big flare up. Dr. suggested going back up to 17.5, it did not help, then 20 same result ... then 30 which finally resolved the worst of the symptoms. By then I had read a lot on this forum and realized that I had been going too fast to taper off the prednisone. It's been an up and down battle since. I have been as low as 7.5 mg but had to go back up again with concerns of GCA. I am now down to 11 mg and have promised myself I won't rush the tapering. I will only go down 1mg at a time for minimum 3 weeks until 5 and then 1/2 at a time. I do hope I get there.
For the last 3 months or so I have been dealing with upper abdominal discomfort, a lot of bloating and gas and acid reflux. The discomfort and sometimes pain starts at the solar plexus and radiates both directions under the ribs. I feel like things are squishing in there and I need to stretch backwards to feel relief. It is pretty constant. Sometimes, especially after I eat, the discomfort goes through to the back.
Though I have kept up my walking between 3 to 5 km daily and have not changed my eating habits, yet I have lost weight about 5lbs in the last 4 months. I thought perhaps my gall bladder or pancreas was acting up.
This morning I had an abdominal ultrasound and apparently all is clear ... which is a big relief ... but leaves more questions than answers as to what is going on.
Could this possibly be a side effect of prednisone? has anyone else experienced this?? I am a healthy (or was ) 75 years old who did a lot of hiking and walking prior to this diagnosis. I follow a healthy diet, I am on pantoprazole 40mg daily which should help with the heartburn?
I will have my first appointment with a Rheumatologist on March 5th, it has been a long wait. Until then I am feeling a bit lost at sea and would appreciate any feedback or advice. Thank you.