I don't have a fear of heights, but if I have not been dealing with it, a ladder or taking a tree down from the top-down,it takes me a few hours before I am totally at ease, stretching over the abyss, or going up on the rungs, or bending branches, you are not supposed to be on, and few days before I start acting like a monkey in a tree.

Continual exposure, may not make you feel at ease, but it may make you more comfortable.