I can understand your frustration, but you returning to your ambulance role is not going to make more ambulances available, more quickly! That is not something that is your responsibility and it is totally outwith your control. Yet, if I were ever in the position of the asthmatic lad or the parents of the query meningitis baby, I am sure I would feel immensely reassured by your being there and very grateful for everything that you were able to do. Anyway, best of luck with whatever you decide.