I just started training today. I know I have a long way to go, and I am excited to develop my body and mind as the years go on. I dealt with a lot of fear issues today as well, and maybe I can help. Practice the things you are scared of in an environment where injuries are less likely. Like rolls on carpet, jumping from one curb to another. When you know you can make the jump/vault/etc without getting hurt, it's much easier to tie that in to your routine, and you push it farther and farther, always knowing that you have practiced it and can do it.
Another thing that may help is knowing that the human body is an extremely resilient machine. We are so scared of hurting ourselves, but it turns out it's actually pretty hard to do. You may get some scraped knees, you may break a finger or two. But in the long run it will heal, and you will know that you had the f#cking cajones to attempt what most people in the world never will.
p.s. get health insurance, it works wonders knowing that you can pay for anything that might happen!