So much of what your W writes reminds me of my D23, who is bipolar. In the bipolar world, the earth revolves around them and their wants at the moment. Anyone who enables them to get what they want is just that: An Enabler. The are usually quite intelligent, but use it for the wrong means. They are not good at relationships. My D23 is about to enter into her 3rd marriage. Pregnant. I can't be happy about another grandchild being born into her hell of a life.
All this just to point out that you seem to be trying to be everything she wants, and you JUST CAN'T DO IT. It won't help you at all, just make you more miserable, and nothing you do will ever satisfy her if she doesn't want to be satisfied.
This may sound cold hearted, but Marriage be Dam'd, stop enabling her. Do it for her as much as for yourself. Work on yourself and what YOU want. If that want is your W, then you are going to have to find another way around it. Withdraw you support, when she comes seeking, out of habit and expectation, set your boundaries. Seek professional help, take meds, or hit the bricks.
I say this from the experience of raising a Bi-Polar child, so I have 23 years of experience. I can't count the times my D has said "I'm leaving and you'll never see me again." The first few times, it leaves you panicked. Now it's just, Yeah. Okay. Whatever. She will come back because I am the safety net, just as you appear to be to your wife.
Decide what you want for yourself. You can't fix her, and she can't be fixed unless she is ready to do the work. Move your focus from her and her life to you and yours. Remember, unless you are a believer otherwise, you only get to go around once.
