That may be a fear of falling. I can't stand to be near a window or on the roof of very tall buildings and then look down. I had a student that was a shrink that figured out I didn't have a fear of heights but a fear of falling instead. I feel secure and have no fear of falling out of a plane, but I fear falling off the roof.
I'm pretty much right there... I can do ladders and climb radio towers (with appropriate safety gear) but I usually end up waking up in a panic at least one night thereafter with the feeling that I was falling.
Especially if the tower climb was difficult... windy, had to go all the way out on a cross-arm while figuring out how to tether off with the safety gear properly -- you're GOING to fall if you miss a step out there, the safety gear is to catch you falling and arrest you relatively gently with anti-shock materials via a d-ring in the center of your back -- or I had a mis-step and caught myself with arms/other leg at all during the climb.
(Haven't had a "real" test of the safety harness yet, and I hope never to... but maybe a forced use of one -- the shock arrest is destroyed in a single use, so I'd have to sacrifice one of them -- done somewhere, somehow, safely, would get me "over it".)
Not my favorite way to wake up, honestly... but I've gotten used to it, knowing it's likely to happen.
Sub-conscious mind attempting to deal with something it doesn't like... that I went and did anyway.
For a guy who likes putting up radio antennas, this annoying fear of falling off of roofs and towers sure can slow me down... I watch some of our climbing guys who have zero fear, and then just chuckle and tell them I'll be along in a minute... I always climb attached, and just do it "correctly"... even though they're up the tower in 20 seconds and I'll be there in about three minutes.
One piece of "kit" another climber gave me that I like, is a seated position Y-lanyard that's made of actual chain link. It's not OSHA approved, but if I have to work in my harness in a seated position I like it a whole lot more than my other lanyards for attaching at the waist d-ring positions. It just feels more sturdy and like it's not going anywhere.
You won't catch me doing any tower work in an old school lineman's belt -- not OSHA approved anymore either, but lots of folks used them and climbed in them for decades -- that many still have and use. Don't really relish the idea of hanging from one of those. My full-body climbing harness suits me just fine.