Dear Diana-You’ve probably just gotten over one of the biggest hurdles-giving that first shot!  I remember a similar experience when I had to scream at the ER doc to give the shot and she let 45 min go by-I had to threaten to do it "myself for the first time"  (I even had the needle and vial with me).  After that experience, my daughter was not quite 2, I decided I would give the shot, then go to the ER, next time.  Of course, there was a next time, and I gave her the shot before going to the ER.  Now, at age 9, I know how much time I have to give her the shot and then have the ped endo call the ER in advance, so they know we’re coming.  That works out best, and I have a very responsive on call ped endo, which helps.  Good luck to you.