I suffer from Health Anxiety.
We've always lived near a hospital in London with a paediatric A and E and knowing we live near it has helped me a lot. I feel reassured it's there when the DCs are ill and although I know that thinking about the 'worst case scenario' is part of the anxiety (and in itself not so healthy) it calms me a bit. My anxiety focusses on my 'missing something' when the DCs are ill and them getting really sick because I have not cared for them well enough. 
We're moving to the countryside, a long way away from hospitals and other services. On anxious days, I don't want to make the move because I don't want to move away from the reassuring presence of our local A&E. On healthy days I'm really excited by it all and can't wait to go.
We have not had a foreign holiday for ages because of similar anxieties about health. We have friends coming on Christmas Eve and I'm anxious that if the DCs get ill I'll have to cancel.
I don't know why I'm posting. Just wondered if any HA sufferers had encountered anything similar.