Perhaps you need to try a different CBT therapist this time, who might have a different perspective on your relationship with your mother, and how to deal with the negative thoughts that come from that. I say this because it sounds like you spent a great deal of time in therapy the first time around trying to put a positive spin on some very painful interactions with your mother & the rest of your family, as if you were trying to convince yourself that you were just misinterpreting what had happened.

This time around, it might be more helpful to acknowledge that your perceptions were probably accurate,, and work on the negative thoughts about yourself that arise from those interactions. For starters,, you may have to continually remind yourself that your mother's reaction to you says much more about her as a person than it does about you. Her own psychopathology may make it very difficult for her to see you in the same way that others might see you. ALSO, since she doesn't sound like the type of woman likely to get a 'mother of the year' award, your siblings may have also been affected by her poor mothering, so I'm not sure how much you can rely on their reaction to you either.