i've had enough
the threshold any one person has when they've had enough.
I can't take this shit anymore, I've had enough!
I've had enough!
This basically means that, the individual have had enough and is going to do a really bad thing. :o
Bitch 1: Ha-ha-ha, you are such a fucking loser.
Dude who had enough: I've had enough!
Dude who had enough: I've had enough!