Hi, these symptoms sound familiar to some of mine, I have gallstones which I have carried with me for many years, with milder symptoms that have escalated since last year and I have been waiting for surgery ever since due to long waiting lists and pushbacks.
I also have a hiatus hernia and a diverticula found on the scans and I had H pylori infection before the situation worsened, which waas treated. So, I don't know what effect these conditions have to add, neither it seems, do the drs as they say it is likely more down to gallbladder, but dizziness etc they say not.
Any abdo conditions may mimic others and many folk with them do report palpitations and dizziness, which may be due to inflammation, gas etc affecting the vagus nerve and pain can also refer along the phrenic nerve, you can look these things up.
I only know that when the gb or whatever other things start to flare, I get light headed, migraines, nausea, palpitation, arm pains, neck and back pain as well as the abdo pain, bloating and general weakness.
At one pint, I had paramedics as I felt my heart was going to stop as it was so fast and pounding, they found then that my heart was fast but OK and the episode was due to my blood sugar dropping rapidly (not a diabetic) so glucose and something to eat put things right. Needless to say I was not eating much at the time, and still can not, though I try to have balanced intakes now and include nutritional drinks and probiotics and carry glucose sweets in case any signs appear of low blood sugar.
Not sure if it helps, but I do think the symptoms are connected but we are all different and the conditions can occur with other digestive and health issues.
Are the drs doing anything about the gallstones?