First thing, have you got your own tools, I don't mean a halfords special, if you want to go contracting you will need a full set of tools, some places expect you to have your own windy drills etc.
I'm being honest not rude you need more experience, I would suggest if you can to keep going the way you are and build up your experience.
Remember a lot of people with a lot of experience have been the subject of cutbacks in the last 12-18 months so, unfortunately there are a lot of people out there looking for work at the moment.
It may be worth dropping one of the agencies a line and ask for their advise.
Hope that helps.