You need to feed what works for the moment being, I can't or won't does not matter when it comes getting your animal to eat for you, you have to do what you need to do and owning a snake means being willing to feed live since not all snakes will switch to F/T.
As Dave stated you will more likely to be successful in switching if you feed what was previously offered and than once established in you care attempt to switch and of course in the meantime no handling.