I think horny is an emotion, tied to lust and it causes the erection. I don't understand the difference. What I struggle with more is what I read here about "arousal templates". It's like our abuse programmed us to be aroused by what happened to us, and I don't understand that either. Will have to talk to my T about it as I don't understand now what is the right way to think. It seems like it is yet another sucky side effect of abuse. I'm new at T so maybe there are a lot of side effects I don't know about yet and that kind of scares me.
Lao Tzu said: "When I let go of what I am, I become what I might be."