You would be too

Why do you think I'm depressed?
Don't you think that squandering all my mother's retirement money on a business venture that sucks ass is enough of a reason?
Spending every day wracked with guilt because both of you stand to lose everything when this fails.
Watching her sink more money into it because the new head office devised a new menu that requires approx. $3000 be spent on steam tables and freezers.

You wonder why I can't stand to work there anymore?
I'm just watching it all get worse and it makes me physically ill.
I don't sleep at night, I feel like throwing up and I cry when I think about it.

Is that enough of an explanation?