Husband can't forgive the wife

How can I get beyond my spouse's critical attitude and forget about the many cruel things she's said to me in the past? After several years of marriage, I've come to point where I just can't take it anymore. I don't believe in divorce, so we're sleeping in separate rooms and living separate lives under the same roof. Now she wants me to forgive her so that we can move forward in our marriage, but from my perspective it's not quite that easy. Her cutting words still burn in my memory, and I'm not ready to become vulnerable again. What should I do?