Ask HN: Maximum bang in 3 months?

Coding in the evenings wasn't working out so I have quit the day job and can float by at least the rest of the year. I've been a half decent developer, I can get anything working if I stick my mind to it, but I haven't been finding much satisfaction in that lately.

The idea is to make it on my own, plan B is to find some high energy flexible job -- typing code 9 to 5 was just killing me.

The question: what can I learn or do in 3-4 months for maximum success further on? Code related or not. Take success to mean what it does for you -- happiness, career, status, money.

I have the time and the energy, but I get the feeling that many things I could be doing haven't even crossed my mind. What would you do with 3 months just like that?

Thanks! I vastly appreciate the input.