I don't think I know enough about what I do, to go contracting but enough for permanent
Contractors are not necessarily experienced professionals, they are merely people who prefer the money/lifestyle associated with temporary and adhoc work. When I switched to contracting, I had 4 years experience in perm roles and was 24.
If you feel you're week at what you do then make yourself stronger. It doesn't always cost money to better oneself. Especially not nowadays. Your success lies in how much you push yourself towards achieving the highest possible goal. Nobody is born clever.
All the best