Hi Infernoland,
I'm sorry for what brings you here, and glad you found the site.
I wish I'd known about BPD years ago. I would've worked on doing more then.
It's good you discovered it now, too! It sounds like it's been a relief to learn there is a name that summarizes what are very confusing behaviors. So much is counter-intuitive in these relationships, and despite our best intentions, we can easily make things worse.
I think it was that my wife was invalidating to her mother when they had a few discussions on a visit last summer. Her mother became very defensive and angry, but then didn't discuss or resolve the issue. Later sent a letter that she will not speak to her daughter again till she apologizes. I guess that's separate from my immediate issue (my spouse and children, but I think that discussing what her mother has will help her realize she has it too).
Could this be foreshadowing what might happen if you suggest to your wife she has BPD?