Cant stop crying, boss will kill me

[LadyFailure]

Im working on a task that should have been done by 5pm when I left the office. has to be done by morning at the latest and i cant do it. It isn't part of my regular job, using a skill I just don't have, so I'm really slow and so exhausted and am in serious shit if I don't produce the work finished. I estimate I need another ten hours and it needs to be in for 9.

Dunno what to do, I love my job but this kind of shit is awful.

Train them don't blame them was the mantra where I was a manager many years ago.
Nowadays at work I won't take anything on unless I have been properly trained and I'm confident that i can do it.
Don't let anyone walk all over you, stand up for yourself, you can't get a warning for someone else's failure to ensure you are capable of doing a task.

Do you work in a law firm or something?