Hi, are you afraid of heights? It's called acrophobia...
I do not like to be up high if i can help it - in a building it doesn't bother me, but everything else does.
So would a roller coaster bother you?
Oh no, I HATE roller coasters.  Cannot stand them - the height, the dips, the upside down tunnels, they all scare me.
What is it exactly that you fear?  Is it the fear of falling?