Good luck with your operation. Just one word of caution before you rebook. Check that you will be covered properly, as depending on your operation, you could find that you are considered to have pre-existing conditions. Do not book first and then do insurance - check that you can be properly covered first. A lot of companies charge much more, or refuse to cover certain conditions if you have had an operation within 6 months of travelling.
There are plenty of companies that do insure, and this may not apply to you anyway.
Hope all goes well, Corfu will still be there when you are well again.