define 'pretty bad'.
if you just had lateral ligament damage, the ankle will still be unstable to a degree, but your boot should act as an external fixator and other than some discomfort, it shouldnt affect your skiing.
but if you broke it or if you had it immobilised for a period, you may also have some muscle wasting which may affect your ability to push with that edge.
also, if you have residual swelling it may cause some pressure in your boot.
give me some more info and ill try and help you out.