She was using sex abusively for at least ten years before porn came up.

She turned sex off like a switch as soon as you got married.

She was cruel and in bad mental health before porn.

Whatever porn did was nothing compared to whatever made her the way she was ever since you were married.

I am skeptical that porn injured her. I think it much more likely that she was secretly at peace with having a permanent cudgel to use against you.