I guess it doesn't really matter. As UC said, it's probably not all that productive to spend time thinking about why she's acting the way she is.
Steve the challenge for you is to embrace that you may never know exactly what happened with W. She may never know what happened either, and you need to accept that on face value. Some things can't be explained.
This can create tremendous anxiety because you can't guarantee that it won't happen again.
So what can you do? First, figure out how to be okay not being in a relationship. If you do that, you don't need the relationship, you're there because you want to be. Secondly, figure out how to "bring it" and be a partner only a fool would leave. If you do that, and you know you're bringing it, then if they leave you it is their loss and you know that, and don't have any regrets.
You can get there, and you'll be fine.
"Having your needs met" is a tricky business. Just like complaints, there are things your spouse should do for you, and there are things you should be able to do for yourself.
If you take something you should be able to do for yourself, like have healthy self-esteem, and assign your partner responsibility for that, it causes things to start to break down.
i.e. "I need you to tell me you love me and buy me a gift every day so I feel good about myself" may be an unspoken expectation of a low self-esteem spouse.
If the partner fails to deliver, they'll get increasingly resentful and blame the fact that they don't feel good about themselves on their spouse for not meeting their needs.
If an impartial judge was involved, they might be able to right away point out that those expectations are unreasonable, and really the person needs to do the work to feel good about themselves without a daily "I love you" and a gift.
Sadly such judges are in short supply and generally unwelcome. We can do what we can to provide for our spouses' needs, but we need to stop short of becoming emotional caretakers, or codependent crutches in order to maintain healthy boundaries.
Unfortunately this dynamic tends to play out unspoken, and with low self-awareness, which is why we find ourselves here, and why marriage is so difficult!
The majority of the battle is getting emotionally healthy ourselves, and that is firmly within our control. This is a one-sided description of the dynamic that's going on. The presumption is that the husband is happy and having his needs met while this is going on, but that's rarely the case. Both happiness and misery are contagious.
