How do you get over being scared to shoot a whole roll?

I load a roll and then I just do not shoot it. Every frame costs money to develop, so I stand there waiting for something worth spending a click on, and it never quite arrives. There is a roll that has been in my camera since April. I have taken four photos on it. How do the rest of you get past this? I want to be the person who shoots freely and learns from the misses, but my brain treats every frame like it is the last one on earth.