Another thing you must not forget is solitude of freelancing, sitting in front of your PC, sometimes for a weeks on end not speaking to anybody face to face just over the phone. If you are a very social person you will struggle.
Also you need to get an accountant to sort out your financial stuff, more money you need.
The other thing you must not forget is your electical bill which will more then double if you are rendering a lot.
Cheers
Renato