I tend to agree with Oliviab above that forgiveness may not be the only path. What does it mean anyway, that we arrive at a point when we no longer think/feel that the act of someone abusive, or even well-meaning but ignorant, was fine and did not cause harm at the time or even lasting harm? My own opinion and approach to these things is not about forgiveness per se, more about recognizing that some things that happened in the past are not relevant to my life today because I have 100% choice and power to decide and act differently and independently, including independently of some momentary feelings that do no more but hold me back. So, for me, it is about the recognition of my choice and moving on. I also don't generally think that it is too often beneficial to revisit the far past endlessly, I do not believe it is possible to significantly "reprocess" those things in the sense that we arrive at some neutral state about them. I think it is very healthy to recognize how the past has contributed to present struggles, but it is not too healthy to claim forever that "this thing happened, so I became this way, can't help it and if you do not agree, you are wrong".

I might have said this in response to you somewhere, LT: I think it can be very helpful to recognize that persistent, life-long anxiety is a physiological condition, much like a heart condition or diabetes. It may have developed as a result of nature+nurture, but it is the reality now and is unlikely to completely disappear. It's more about how it is managed and it cannot really be managed purely by explaining its causes. It can be improved by coping with things differently and shifting perspective. Trying new things. I still tend to think that this therapist helps you, in a large part because he is so different from you and gives quite different feedback from what you might automatically seek (e.g. from MC in the past) and because he sticks with his approach and does not alter it in big ways just to please a client or to become what they client wants (as many Ts, IMO).

If forgiveness does not appeal to you, I would say try out a concept that feels more compatible. As I said, for me it is usually moving on (I like that one because it implies both acceptance and progression). What could be the alternative anyway regarding your mom and her effects?