My dad and I are both afraid of heights.
You have a fear, this fear is scary, oh, and it's a symptom, so it's kind of just in your head. What kind of symptoms occur when you are scared and have fear? How about when you have a phobia.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.