How do I stop my cat from ruining my house?

My tortoiseshell Tabatha is a chronic scratcher. I have had her for 3 years but in the last few weeks the problem has gotten out of control. Everything, items, walls e.t.c. that can be scratched is being destroyed and it is costing me a fortune. My savings are being eroded repairing the damage and will soon be gone. I am at the point where I am considering driving her out into the countryside and leaving her in a box. I am going to give her a week to improve then that is it.