Sophie I have been experiencing something very similar to what you are describing (not everything the same, but alot of it). I have been having the high heart rate or what feels to me like "heart pounding out of my chest" that has scared me quite a few times. The difference for me though, is that it doesnt have to be when I have eaten, it can be several hours after I have eaten---and instead of the restleness you describe, I get extremely fatigued like I have to lay down (and do so if it wont stop). The achiness in the legs is the same for me, it feels like an ache in my leg bones, the way they ache when you feel sick with the flu or something. Ive also been having on and off pain in my RUQ as well.
I had a Doctors appt. yesterday to get the results of a CT Scan I had, and it has left me just as confused as before! I had an XRay (abdomen) last month that showed Large Intestine partial blockage from chronic constipation (yet I have diarrhea at times, strange, since you mention this also), and a "spot" near my left kidney. Yet the follow-up CT Scan showed a "growth" that looked closer to my diaphragm. The doctor said this could be a Gallstone, but the location was a bit off, and the UltraSound I had a few months ago showed my Gall Bladder as being clear. Still, she said based on the CT she is "leaning toward Gall Bladder problems, but wants to make sure because some things dont fit" like a few symptoms as well as the Scans not jiving with each other.
So....I am waiting for her to "discuss it with other doctors" (I wonder who she means, exactly, lol) and let me know what to do next. In the meantime, I have also for the last two months been experiencing a recurrent Gout problem (2 weeks of which were absolutely painful). My doctor thinks these things are all related, as issues with both Kidney (directly) & Gall Bladder (indirectly) can interfere with Uric Acid levels and its removal from the body (Gout, leg cramps/achiness); I believe she is on the right path--that they're all related somehow.
I might be forgetting some other details, but I think those are the main points, and they sounded similar to your description Sophie. Perhaps we have some common problems...or else theyre different but causing similar symptoms! Let me know where you stand or if you learn anything new Sophie, and I will do the same? Maybe together we can get closer to finding out how to take care of these problems we have, and get back to feeling a bit healthier!!