When they say "ILYBNILWY", it's typically, but not always, because they have a point of comparison. It's wayward wife speak for I love someone else now.
If there is an OM is quite likely a married (or now divorcing) man, probably a co-worker (because it's easiest to hide). She's invested in getting a divorce BEFORE announcing her new found love to the world and the only reason a woman typically does this ( waiting) is because the OM is still married trying to sort out his situation without telling anyone. Perhaps he has no intention of divorcing his wife and your wife is content being his mistress.
Her accusations towards you about your suspected affair a couple years ago give her a good excuse and fill up her rationalizations and justifications just enough to allow her to divorce and abandon you.
I hope I'm wrong. Infidelity [censored]. Her illness and near death experience has likely shaken up her world view (or damaged her emotionally and physically) that she's now losing her competence.
Then again, if I'm right you have an explanation for your situation and can then make decisions about your life from there.
The internet is 90% complaining and entitlement and I hate it because I deserve better!