Betty needs leg amputation :'(

On Friday July 25th, I got home to Betty with her back paw tangled in blinds cords. I have no idea how long she was hanging from there with the cord wrapped tightly around her back right paw. I freed her and then she was dragging her leg as there was no more bloodflow to it. Her foot got swollen, infected and she is still not walking on it. The vet said needs to get the whole leg amputated because the end of her paw is dead and drying up. This will cost close to $1800. I'm looking for some help.. anything will be helpful! Thank you so much!