Divorce, guilt and my adult children.

My 20 years marriage has fallen apart several years ago and my husband wants to divorce now. I have been wanting that for some time but now that he is asking, I am feeling extremely sad and guilty as well. I have watched the “loving the unlovable” on the podcast live and it made me feel so bad because I feel that I wasn’t loving these last years . I think that I have ruined this marriage and that my children (19 years old twins) are now suffering because of the tension between my husband and I. Tension that I have created.

Unintentional model:
C: Marriage/divorce
T: I have ruined my marriage
F: Guilt
A: Spiraling and indulging in sadness. I am being very aggressive when talking about /to my husband and have a hard time managing my emotion when kids talk about him.
R: the children are caught in the middle of the conflict

intentional model??
C: marriage/divorce
T: I did my best with what I knew at the time
F: compassion
A; work on myself, focus on daily tasks and show compassion to kids and my husband
R: The children are free to love us both without needing to choose between us.

Any guidance on my models or suggestions on how to manage my thoughts ?
thank you