At The End Of Your Rope!
Estar a Punto de Caer al Abismo
This means to be at the limit of your endurance. Not to be able to resist or tolerate a situation any longer.
If you were a climber using a rope at a mountain, in order to get to the top, and you were at the very benning of it, you could probably go up or down as you wish. But if you were at the very end of it, you would not afford yourself to go down any more or you would fall down to a sure death.
Claudia has done everything possible to save her relationship with Michael, in spite of his terrible habit of drinking alcohol in excess. She has tried to help him in many different ways but nothing has worked out. Now, they will start a new rehabilitation therapy but if it does not work out well, she will leave him for good. She says that she is at the end of her rope.