Hey purple avocado, My suggestion: don't pretend. Be authentic and tell her its over. Listen to your gut feelings. Think from the neck down, which is what you are doing:
my physical reaction tells me that it isn't right to be in regular contact.
Don't sugarcoat it. Set up a Boundary that meets your needs. By responding, you are only encouraging her to proceed with some form of manipulation, i.e., F-O-G. Has she guilt-tripped you, claimed you owe her, love-bombed you, or otherwise tried to yank your chain? Of course she has.
Don't fall for it, my friend.
LuckyJim