Hello
I also struggle with similar issues. With vertigo, fear of heights, fear of open spaces - whatever it's called.
Personally, in the mountains the most important thing for me is to return to the starting point. Whether I "conquer" the summit or not. Oh, and I've already done the "lower" hills.
But somehow I manage. It started with Komarča. A colleague described the path as easy. For him. I thought on the way that I'd at least die. So hiking in the Valley of the Triglav Lakes turned into a nightmare because due to time pressure I had to go back over Komarča again.
Since my better half doesn't have these issues and doesn't know them, we now have the following recipe. On these pages we look for a summit or path I'd like to hike and seriously study the entire path at home with the map. If I see exposure marks, I check on this site what's waiting on that part of the path.
Later in the mountains I go ahead alone and literally "acclimatize". And after some time I get a feeling if I can manage the continuation of the path (and return to the start). Then I give the "signal" to my better half to join me. And then slowly but surely forward.
And if I'm too slow for the others, we step aside. The important thing is that I feel safe. And this way we managed to hike from Koča na Prehodavcih over Tičarica and Zelnarica to Komarča. And during that I even enjoyed it for about an hour looking into the Valley of Triglav Lakes.
I have to admit though that this fear requires really a lot of inner struggle. But next time I'll definitely try with an experienced mountain guide. Maybe this way I shake off at least part of this fear.
Good luck.