I know how you feel B. I truly do. But here's the thing - WW rewrite marriage history to rationalize and justify their actions. They exaggerate issues as if they are mountains, but they are actually hills that could've been summited if they were addressed in a timely manner. Okay, so you didn't listen and didn't do this and that. Now is your opportunity to turn that around for yourself.
The other thing about blaming yourself is this. AS had explained it really well in my threads when I was going through the same thing as you. We talk about the WW 'fog' here quite a bit. Some find it offensive, but I generally use it to describe their state of mind as if something has overtaken it temporarily and they are not being themselves.
The thing about this 'fog' is that both the WW and LBS are in it after BD, but in the exact opposite directions. WW externalizes all accountability for her actions and projects everything on to the LBS. The LBS internalizes everything and projects all the faults on to themselves. They have the WW on a pedestal and see the marriage through colored glasses. When the LBS takes time, space, does NC/dark, and GAL, the shine off the marriage comes off and the fog they are in starts to dissipate and they can see the marriage for what it actually was. They realize they were also unhappy for x reasons and that the WW was not a suitable partner for them as well. The LBS fog doesn't just magically lift - you have to put in work and trust the process. You have to focus on yourself.
The WW fog is not something you can directly affect. She has to go through it and come out on her own timeline. She has to feel some loss and her fantasy has to get shattered.
So, what to do about it for the LBS? You should acknowledge how you're feeling right now. But don't wallow in self-pity. Acknowledge you may not be seeing things the way they really were. That you're looking through the lens of pain and hurt and loss of control. That's not going to make it disappear, but if you recognize and name it, then you will be able to engage in positive self-talk to get past it.
But in this stage, GAL, NC/Dark is the name of the game. Trust me, that's the only thing that allowed me to get past this. So, just know that you're not operating in reality right now. Your mind is in survival mode and you want to get back that control desperately.
Take the gift of time and space. I know it doesn't feel like a gift right now, but it really is. The timeline for this is long. The space is crucial so that you can get your head straight. If you're like me, you are great at beating yourself up. Start practicing self-compassion as well. It takes two to make a marriage work and fail. She is also accountable.