I had my chemo in 2013, but didn't want you to be left with nobody responding to your queries. Your throat and heartburn issues sound very familiar! I was given tablets by the GP, which I still take, which sorted them out -- so do discuss them.
The pains in your chemo arm are also familiar! FEC is very hard on your veins. I was told I had "great" veins -- but they were rubbish by the end of chemo and now -- 13 months later -- it is still nearly impossible to get a blood sample from them. Be sure that after your FECis administered, they flush your veins with saline. My hospital was quite good about that, but I have learned since that not every hospital is so through. Stamp you foot and demand it! It will help a lot, but unfortunately there will still be damage. Good news is that the damage is reversible. i am now a lot better off than I was right after chemo -- but it does take a long time.
Good luck on your journey.
With love, Yankee