Savings from my first job out of college (was able to save by living with my parents at the time) and major sacrifices. By the time we started taking salaries, my savings was nearly completed drained. I will say that I was lucky enough not to have to take student loans so I did graduate debt free.
If you don't mind me asking, if the company failed to turn a profit what was your next step? Savings gone, no money coming in, living with your parents and not being actively sought after. It sounds like you went "all in" which is very admirable.
Honestly, I had no backup plan. All I could think about is making my startup succeed. Because I made failure not an option, I was willing to pivot twice instead of giving up. But I had nightmares about running out of cash. I was scared.