Hi Lauren. Welcome aboard...
I doubt there is one of us who cant relate to your loss. I have been doing this a very long time, and still screw up a bid occasionally, and lose my ass.
It always hurts... but I chalk it up to experience, and try to be more accurate on the next one.
The worst one ever was in 1996.
I was painting a strip club (seriously) in N. Holywood CA. (my home town) and after all was said and done... I ended up making about $600.00 for 3 weeks of work. Literally... I had 120+ hours into the job.
My guys got paid, and the materials got paid for... but the good ol' owner (me) made $600.00!
I seriously considered getting out of the painting business at the end of that job. But...
I took some time off and examined where I went wrong on that job... The next gig, I did just fine.
I suppose Im not the smartest business man in the world... but I make a decent living. I just need to be more detailed in my estimating.
Anyway... good luck... and dont get discouraged. We all screw up sometimes!
Matt