I have the feeling of a lump at the bottom of my throat and a lot of burping. Is it GERD or gastritis?

Hi doctor,

I am a 30 years old female, my height is 4feet 9 inches, and I weigh 224 lbs. I am intentionally losing weight, and I was 238 lbs previously. I have a heavy feeling in the chest. I have the feeling of a lump at the bottom of my throat and a lot of burping. This happens on a full and empty stomach, regardless. This is happening for about three weeks. I do not have any pain or burning anywhere. My general practitioner said it is a symptom of GERD or gastritis and prescribed PPI's (Omeprazole 20 mg). Still, I have not taken it at all, because I read it has serious side effects. I then tried to check my stomach acid levels with a bicarbonate test, because I remembered that an allergist told me years ago that I have low stomach acid. This seems to be correct, as when doing the bicarb test, I do not burp for over five minutes (I have done the test twice). I want to find out:

What does it mean to have my kind of symptoms? Is it GERD? Does my type of symptoms affect my lungs at all?

Is it possible that low and not high stomach acid is causing my non-traditional symptoms (as I do not have any burning or pain), even on an empty stomach?

If low stomach acid is the issue, should I treat that first? (I read about Hydrochloric acid and Pepsin supplements and digestive bitters).

Or should I treat my symptoms first? Can I use H2 blockers? Is that enough, or should I do something else?

Or can I treat both things, symptoms and low acid, simultaneously?

Should I take any medicine or supplement for these issues, only until I feel better or longer?

I am worried about this, as, if untreated, it can cause other serious issues. Thank you.