As a child, I was terrified of spiders. I'm not sure my family even knew. I think I feared someone finding out and putting spiders in my bed as a joke, or something. I had an older brother, after all.
But in fourth grade, a kid at school brought his pet tarrantula to show-and-tell. Now, he was one of those boys everyone liked at that age. We were in fourth grade, so there were only two categories: boys we liked and boys who were gross. This was a boy we all liked.
So I couldn't admit I hated spiders or that I feared them to this boy. So when it was my turn to look into the spider box, I looked. I didn't squeal or run or cry. I just held my breath, bent my neck a little, looked at the ugly thing for a few seconds and then I smiled at the boy.
That was it. I overcame something in that moment. It took me a lot of years to realize why I could do it in that situation and not in others. It's all about motivation.
In that moment, I was motivated to forget my fear because of the boy. My adult fears are the same way. I have to have a reason to get over my fear and do something that scares me.
So I am editing a manuscript and prepping it to send to an agent. That terrifies me. Rejection scares me. Success scares me. Putting myself out there to be rejected by someone I respect makes me want to run and hide. But the motivation has to be significant enough to make me do this. And getting a book in print (and possibly a paycheck one day) is a huge motivator for me. I want to write for a living. I want these voices out of my head and on paper.
You have to decide what motivates you and focus on that thing.