Most of the time I can feel a knot in my stomach by my diaphragm it usually happens after I eat something or drink fluids.
It seems like it’s heartburn, GERD.
I can feel my heart pumping stronger when I get heartburn.
Heartburn literally feels like there is a fire in your chest. Like a physical burn. The first time it happened to me, I literally thought I was going to die because it hurt so bad. It happens to most people with certain foods, so you might want to keep track of what foods trigger the feeling. If it happens after absolutely anything, with no correlations, that would be something to be concerned about. GERD that comes on suddenly with no prior history can be caused by lots of things, but most commonly anxiety.
If your heart pumps stronger after certain foods, that could mean you are having too much sodium at one time.
Have you tried an over the counter antacid? I use omeprazole once a day in the morning and it works well. Might be easier to just message your doctor and ask if it would be ok to try it on your own.
I think I have it as well. I sometimes get that acid in my throat and chest burning, although I have not had it in awhile. My doctor gave me a prescription medication for it when I brought it up but I have only used it once because it has not been an issue for me lately.
TUMS don’t really do much. Taking a daily preventative like zantac or prilosec (depending on interactions with meds) would give you a better idea. So would keeping a food log and noting what foods cause the issue.