Wow, this is an amazing thread, with some amazing responses. It really resonates with my past life experiences.
I know this is also an older thread, but in case the OP is still listening, this is my advice. It's become clear in this thread, you both have issues. She has been unknowingly pressing your buttons, and you may well be pressing some of hers.
Do not just leave. That would be throwing away 20 years for both of you. You know, this pattern will repeat in your next relationship, plus the new relationship will have additional issues of its own. Neither of your issues will magically resolve on their own, and you each have a perfect participant to aide in resolving your pasts. Relatively quickly. Be honest with her and demand counseling. If she refuses, then tell her you're considering leaving her. Then, demand again. You're on that path already, so what do you have to lose? Hopefully, she will agree.
Find a really good ACT therapist in your area - with a willing partner, it is very powerful. An example of how it works, a good therapist will guide you both through a recent interaction that triggered your abandonment issues. You will start emoting. Then your wife will be asked to not speak. The therapist will start to push you and push you. Why did she do this? Why would she do this? Did it make you feel like this? Did it make you feel like that? And just when you're about to lose it, the therapist will turn to your wife and ask "is this how you intended to make him feel?" Of course, she won't have a clue what you were thinking. She will no doubt say something very affirming. Like "no of course I didn't mean to make you feel that way."
When you're on the brink, and you hear the (present day) cause of your pain (your wife) speak her quiet truth, it is profound. For me, past scenes of abandonment trauma flashed in my head, as if they were being reassigned or saying goodbye. It felt as if my brain was rewiring itself almost to the point of vertigo. I felt my brain literally shaking in my skull. After the emotions subside, you will feel an immediate relief. You will go home looking at her in a completely different light. It will take at least a few sessions for this to be retained long term, so stick with it. Then, it's her turn for you both to tackle her issue(s).
In a short period of time, your relationship will grow to a deep level of love and trust that you would never have dreamed possible. And, the universal issues that are cleared will improve your life outside of the relationship as well. OP if your still listening, I think it's well worth a shot.