That said, I have to ask....are you sure you want to apply to Y Combinator?
There are startup jobs out there where this sort of mismanagement is not the norm. I was in your exact shoes at one point (although I left due to repeated missed paychecks, not due to layoff) - and I began to doubt if any company would be competent, except one I started myself. (This was compounded with my own minor successes in the startup game, having gotten personal momentum with an idea on the side.) It pains me to admit this so publicly...but it took me a year to realize, that my experience there ate away at my trust in anyone as a potential employer.
I guess all I mean to say is, YC is great - but if part of you still wants to join an early startup and learn while you're young, there are good employers out there. They're few and far between...but please don't give up. They're absolutely worth the search.