I'm so sorry you are having difficulties with your marriage. Your wife sounds like my stepmother's and my relationship; both of us anxious/controlling.

If you would like to stay with your wife, I would try to ignore the criticisms, respond with something pleasant ("I wish that were possible!" when she carps about your not working) and just more or less saying something positive and supportive so there's no where for her to go with the criticism.

Being positive in yourself with your statements about yourself, has to shut down her criticism because she can't argue about "you" and what you feel. It's the old "relax" and you are harder to carry off the protest site trick :-)

But it does sound like she is just carrying on from what she learned from her mother. Have you all tried therapy together? With both of you on disability though, sounds like your relationship is more ingrown/together than one would normally be and not much else "exciting" going on? It could be you don't "just let go of your wife" because you can't imagine anything else?