I also have the dreaded fear of falling and heights. These may have come naturally and then been reinforced by a couple of falls. One was with a large car battery while going up a ladder to a boat in storage. The boat whose bottom I had just painted was now less stable than before. As I climbed aboard, the boat shifted, and battery and I were thrown. The battery survived the fall, but I was knocked out and woke up as they were loading me in into an ambulance.
One thing that has helped, and came as a surprise to Peter Spangenberg, is that I carry an assortment of old dock lines in the car. When wishing to photograph a waterfall while looking down from a cliff edge, Peter was quite surprised when I returned from the car with a heavy line for me and another for the camera. Once we were tied off to a tree I felt much better about the situation. The panoramic scene filled the 7x17 frame and was dramatic. My shorts however were not filled. My body, brain and camera survived the event unscathed. Once I knew I could not fall beyond the length of the tether I was okay. Try it near a very short drop to see if it works for you. If it works there, increase the drop distance, until you know what the limits are for you. Be sure that you know how to tie good sailor knots.