That is fairly common for a lot of people that have not been able to spend much time around horses. Hell, when I first started working with horses I was afraid of stallions (because of all the bad things I heard about them from non zoos).
I got a job cleaning stalls to be around the mares and geldings first, got used to them, started hanging out with stallions, now I make my living working with stallions.
It is all am matter of getting around them and getting used to them.
That is part of why I offer for people to come to my place to help care for my horses. It gets me help that I cannot afford to pay a normal worker, and at the same time lets zoos that don't have experience around horses gain that experience.
Start at the basics and work up.