Don't worry, you'll soon get used to doing injections. One of my sons is a severe hemophiliac and I had to start injecting him intravenously at the age of two! It was hard for a while until he came to accept it and stopped struggling. At around 10 he started giving himself his infusions and it has now become routine - he's 20. And hitting a vein is pretty hard - much more difficult than just an intramuscular injection. That part of it will soon be a piece of cake.