You think you are the best, but you are still scared? You just need to work harder they tell you, and visualize what you want until you WILL it into a glorious manifestation.. You now have two opposing beliefs your mind that are vying to be acknowledged as real: what you wish reality could look like, and what you know deep down as true. This begins the fight you start with yourself.
The implication behind self-help and doing things like affirmations or visualization is that it reinforces the belief that you are not enough as you are. But you are already someone of value now, trying to add or subtract from this natural truth is the cause of fear, insecurity and call reluctance. Don't focus on a negative. Instead, my perspective on selling is that: 'I may not succeed, but there is no way I could fail.' My second belief is that: "If it can be done at all, I can do it. If it doesn't work, then I guess it couldn't be done.' A little delusional perhaps, but empowering.
Adding pressure and wilfulness to a situation where you are already feeling anxious is not going to eventually make the fear go away. Being courageous and facing the same fear each day is not going to make you feel better. Making calls is not a big deal, so don't view it as facing your fears, just get on with it.