At the beginning there was discussion about how detachment is part of fixing you, but cannot fix the marriage or the partner.
I'd add that while detachment will not fix the r/s, enmeshment nearly rules out a healthy r/s.
When she's dysregulated I feel the pain too.
You notice her pain. With dysregulation, it is obvious!
What happens in you next?
Feeling the pain like it is yours? -- Enmeshment
Fearing what will come at you next? -- Also Enmeshment
Not being able to feel anything, or perhaps relief at avoiding it? -- Indifference, perhaps? Detachment, but without the love?
Feeling sorry for her? -- Pity
Lovingly caring that she is hurting? -- Compassion
It is a learning/growing process for you to work through (I don't know that you will go through them all, or in any particular order). I hope you make it to the point of feeling compassion for her. Whatever happens to your marriage.