Hello and welcome,
Foxybluejay 
I am one of those "old dogs" who has learned "new tricks." It took me a long, long time but better late than never.
I, too, have an adult daughter who many times over the years has withdrawn from any relationships with us. We are currently in a 2-year stand-off...others have been longer. In the early years when we would also lose contact with our precious, little grandchildren, the heartache was excruciating.
Same as you, our daughter blames me for all her woes in life while her father, in her eyes, is her hero. With that said, it has always been me she has run to when she needed help...not her father. Consequently we have had times of friction in our marriage.
I applaud you in that you are seeing a therapist. It took me a long time to do that. When I did, though, it was life-changing for me. I needed someone who listened, understood and validated me. It was life-changing when I found this forum...the support and validation I get here reinforces the one-on-one I had with the counsellor.
When in one of her rages, our daughter's mode of communication is emails. My heart starts to pound when I go on my computer and see her name. I know what I will read will not be to my favour.
One of the more important "new tricks" I have learned here is not to JADE. That is...do not...Justify-Argue-Deny-Explain. That is when I would get into one of those "no-wins." Mind you, even though I will now just answer her emails with comments like..."I love you"...her rage seems to escalate.
"Stop taking things personally"...for sure! I played the role of Victim opposite my daughter's role of Bully for so long. She found my buttons, pushed them and I reacted. Certainly there was no need for her to change. All was up to me.
Once again, welcome Foxybluejay. Hope you stay. Hope you take the time to explore this website...feel your way around...read the posts...jump in to respond when the spirit moves you...keep sharing what is going on in your life with this "challenging" daughter of yours. Many times it has given me great comfort to put my fingers on the keyboard and pour out my heart and my hurts...writing thoughts that I have not been able to share with friends/relatives.
From one Mom to another...a ((HUG)
Huat