Are you in IC? You sound depressed... from my own experience my depression led me to have a very irrational and distorted view of myself... and I also felt very hopeless.
If you are not seeing an IC, I urge you to get help immediately.
Please keep in mind that, while you do bear your share of responsibility for your relationship with W, she has played a role, too. This is not 100% your fault. You can only control you. But you CAN control you.
With help, you CAN change negative thought patterns and develop tools to help you manage R better-- not just with W but with everyone in your life.
You are not a terrible person, and you do not need to suffer alone.