Between subcontracting from established freelancer friends and reaching out to my network I was able to get a few projects, and things were progressing nicely but then my biggest single client had some internal issues and basically didn't pay me for 6 months.
My financial situation going into freelancing was not good - I had some debt going in, and then put some incidental expenses like visiting a customer's city and staying in a (cheap and amazingly nasty) hotel for a few weeks on a credit card. The gap between invoicing the work and getting paid was too much and I realised I needed reliable cash flow.
They say the main reason businesses fail is lack of capital. Turns out starting a business with negative capital is hard. Too hard for me.