Sheepish, oh dear how is the ewe & have you had a vet out yet??
Where in the world are you, as there are some really good products available for the aftermath of flystrike depending on where you are.
We had two ewes affected here and not knowing what to do we panicked a little and as others have suggested cut away the affected fleece and applied a detergent, diluted with water, that is used to delouse chicken houses. It is a sort of pine oil product and it really worked well. Horrifically the maggots were falling out of the sheep as if it was a horror film, really sickening but and a big but it worked.
After the event we were told of a really good product called Aluspray which is available from chemists here in France, maybe available elsewhere??
Good luck and please let us know how things go.