We have 6 senses. You know of the five physical ones. The 6th is you emotions. Just like touching a hot stove will activate your sense of touch, fear can be useful. It can also be debilitating.
To separate good fear from bad fear ask yourself; "Is this chronic?"
Chronic fear is what you suffer from constantly. Fear of taking on a new job, fear of trying the technique, fear of being rejected when asking for what you want. You feel chronic fear every time you think of the topic.
To defeat this, you don't need to know what to do. That's the rub. Trying to muster up the courage to take action will only increase the fear and paralyze you.
Instead you only need to know why you are feeling this fear. Once you know what thought pattern is creating the fear you can shift quickly.
Chronic fear is caused when you have a desire, something you really want to obtain or achieve... and you say "no" to it. The language loops sound like this... "I want it, but..." "I'm trying to..." "I want to but...." "I need..." "I'm waiting for..."
The cure is to identify your desire, then identify how accomplishing that desire will make you feel.
Then create that feeling now.