impossible for most people. shes being incredibly selfish by being aware of your attraction, not reciprocating, and still demanding your time and attention. all of these factors point to complete and utter disaster. easiest and smartest thing to do would be to cut off all relations with her.

it may be painful to lose a friend in the short-term, but even you should be able to see that youre being used in this case. on the plus side, if you decide to end your friendship, she may realize that she does need you romantically. in either case you would save yourself a lot of mental anguish by (at least temporarily) removing her from your life.