think most people are fine, the main side effect seems to be a bit of fatigue but having to see someone is a good idea...good to hear that you are feeling brighter in yourself.
usually for anaemia..... I used to have monthly injections when I was very young (still can remember a nurse missing my vein at Lancaster Hospital) plus I had to eat rare liver twice a week (which I liked) and codliver oil in the form of miniature rugby balls! Last had a touch after having measles in my teens.