I'm afraid of my emotions just shutting off at the worst time.
What would that "worst" time be?
Mostly, I worry about when I have a girlfriend. I worry she'll leave me if my behavior changes too much.
Everyone is afraid of something. When you recognize the fear, you can realize that you have power to not let it control you.
I'm still afraid of change.
It's not easy to face your fears, but if you let them fester unaddressed then they'll only grow bigger. A good first step would be to seek out counseling to help you get to the bottom of your fears.