Unless you don't intend to work again, have enough capital and is sufficient enough to absorb losses, I wouldnt advise starting a business just yet. Weigh the pros and con's apart then you can really decide which would pay you better in the long run.
We don't need to be discouraged from starting our own businesses. Op seem to have had experience from working for somebody and wants to take a necessary risk and chances are there that he can succeed if he gradually go in for it. He doesn't need to stop his work entirely but can reduce the rate of focus and divert his strength, energy, ability and ideas to grow his business. At least now he is a freelancer, so he has more control of his time.