I've read most of it, I guess considering all the super serious issues I've witnessed that destroy marriages, my assumption was that there had to be more to it than just this.. There's cheating, cucking, extortion, child manipulation, in-law wars, frigidity, etc. I mean I can understand your frustration over this, but it just ranks pretty low in the spectrum of "my marriage is coming to an end because X".
But to each his/her own I guess in regards to what's important. Guys were ragging on you because your wife bought you underwear, but to be honest with you that's actual evidence that your wife cares and thinks about you. One of the "tests" I use on any chick I'm dating long term (and most fail) is to see if they offer to pick me up some T-shirts or socks while they are at the mall after they remark that my socks have holes in them.
If she used to be flirty/slutty, then I guess the potential is there, you just need to rediscover it. Maybe try some sub/dom stuff, she sounds like the type that would be into it.