LTS - Oh yes, I made a full recovery. I was ready to return to work two days later. For me, it was a breeze. I tried the medication first but it didn't work out and I refused the radioactive iodine for various reasons. So for me, surgery was the only option based on my situation at the time. Looking back, the only thing I'd do differently is have the surgery earlier. But, everyone is different with different life experiences so you have to choose what's best for you. Sorry, I got off on a bit of a tangent there.
Oddly enough, I never thought the "pounding heart" was an issue. I think I had lived with the problem long enough to think it was normal. It wasn't until after the surgery that I realized that it wasn't. I would get out of breath while running as well - I would have been the unfit lump, too.
Hopefully, you'll meet with your endo soon and can get it all sorted out.
I had Graves Disease ended up getting my thyroid completely removed in 2009. Best (personal) decision I ever made. My endo advised no running at all while dealing with Graves Disease. I don't know if she was overreacting or just being cautious. One of the only side effects I noticed was my racing heart. Even when lying still near my husband, he used to tell me if felt like my heart was beating out of my chest. I assume my doctor was just being cautious but it may be something to speak to your doctor about.
I was the opposite from you regarding weight loss. I had a problem losing weight while dealing with Graves Disease. I was always hungry. I actually lost weight once I had my thyroid removed and my body returned to normal. I'm not saying this will happen to you but it was my experience.