Well, I want to really thank each and every one of you who responded. This really helped me. I wasn't sure if I was the only one. These phobias are, like many things in mental health, not always outwardly revealed by the people suffering. Sometimes we are ashamed. I'm a grown man. Why should I be afraid of a little height? So on. After reading that nice article referred to by @
chainwhip, I definitely do have many of the criteria, no doubt. Anyhow, I will take all these suggestions into account. They are all good. I am going back up that big hill in a couple days. And we'll see what happens. Maybe I need a therapist, though I must say, this fear is so profound, I cannot imagine it ever going away.