The only step I can take is to begin initiating D proceedings myself
Right now I think that is exactly what she wants - to get D'd without taking responsibility for doing so.
You can make this all about her taking responsiblity and professing your love at the same time. I like the way Gucci says it. You probably ned to find a quote of his but it's something like this: "Wife, I will not share you with another man. If that is what you want then I will gladly intitiate a divorce. I know that I will have no problem finding another woman to love and respect me." Then detach and become very mysterious. Start the D process. Your marriage is not going to be saved in it's current state. Retro won't help if she is in this mindset. Thinker you don't control all of the cards, you have to play what you are dealt. You can handle it.
Cheers
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.