That wasn't at all the problem for me in the first years of bootstrapping. I didn't invest with my own capital, but by putting my spare time into it. Funding was provided by the early customers. I kept working full time for my previous employer for one year, then part time the second and third year with decreasing hours.

Also now that its running on its own, I also feel that I have less risk, because with a profitable company there is no requirement for growing a specific amount that investors demand or otherwise they take your control away.