Here's the email--T embedded his replies in what I wrote, so I just made it like a conversation (hopefully the blue shows up OK):
"T: LT, I put my responses into your email below in blue. No worries on my end about sending the email in the evening, you can feel welcome to email whenever it's comfortable for you to do so.

Me: Hi Dr. T,
I feel really awful right now, lots of sadness, maybe some rejection from your end, some self-loathing. It's really hard to hear you to talk about forgiving my Mom because it feels like that invalidates my experience (even if I get what you're going for). Even worse was your saying that maybe I was a difficult child to raise (because of my anxiety), which felt like it put the blame on me and exonerated my mom and dad.

​T: I think that the path towards your greater mental health includes forgiving you Mom, and doing so will be more for your benefit than for her benefit. I'm sorry if you feel as though saying that, for your Mom, you may have been a difficult child to raise. I can see that it was hard for you to hear - but I think that it's true. That doesn't make you a bad child, or even a difficult child if don't like that language, it means that for your mother you were difficult to raise. I think that your issues with anxiety and her issues with anxiety made for a difficult match. For example, she tried to control your behavior and deny your mental health issues as a way of calming her own anxiety and perhaps giving you the tools that 'worked for her'. But they were the opposite of what you felt you needed. That's a bad match, and I'm sure it was frustrating for your mother in addition to being extremely hard on you.

Notice that this is not about blame, who was right and who was wrong, but about the situation itself. It's my professional belief that it is the role of the parent to adapt to the needs of the child, not the other way around. Your mother was unable to do so. That won't change with understanding or forgiveness. Also, I'd want you to see that there is no black/white; all/nothing going on here. It's not about all the blame going to one person, or exoneration for your parents. It's about appreciating the complexity of human motivation, behavior, and development and being able to see how things are rarely simple. The more you come to learn about a person, the more their behavior can start to make sense even though you would have preferred that person to make other choices or be different from who they are. Understanding someone and even forgiving them does not mean that you have to believe that everything they did is now fine and you're OK with it.

The thing with paternal transference is...now it feels like you're there in my dad's role, where he's putting my mom's well-being over mine ("I just love her a little more than you," he said at one point, when I'd upset her with my anxiety). ​

That is a pretty bizarre and terrible thing to say to a child.

I'm sorry, I feel like I must be such a challenging client, but this is so ****ing hard for me. The feelings, the transference, the stuff going back to childhood--they're overwhelming at times. I know you're really trying, and I appreciate that. I think I need two things: (1) To know that you at least somewhat understand and sympathize and/or empathize with what I'm going through right now;

​I do appreciate how hard this is for you, but I believe that you will experience greater emotional peace when you are able to go through the process of forgiveness and it starts with seeing things from the perspective of your mother and coming to understand more about her limitations and challenges. Doing so should not invalidate your experience. In fact, my hope is that it would enrichen and broaden your experience. You can begin to see the story of your childhood through several angles, which will lead to wisdom and - eventually - greater compassion for yourself and, I believe, your mother as well.

and (2) a reminder that you'll be there with me for whatever I go through in this therapy process, for however long it takes (within reason, of course). Yes, I should just know and accept (2), and I'm working on it, but it's harder when stuff from my past is triggered. ​

I have no intention of going anywhere. I see this as part of the process, and a difficult one for you, and hopefully you will experience me as being patient and understanding through it.

I understand if you have to charge for this. ​

Thank you for that understanding