Breakdown last month, great this month. Where's that last straw?

[StrongDadOf2]

My wife had a major down event in January.  Enough that friends knew she might be suicidal, too.  Confronting her about it in therapy was surreal.  After 3 days of being completely absent from the house, leaving me in the ever familiar single-dad mode, she was fine.  Happy and ambivalent.  This leaving and coming and raging and happy spun my anxiety-disordered son into a major breakdown, necessitating forced time off from school for him to recover.  At that point, I had told myself that this was the last straw and she must get out.

But, this month, she's engaging with the kids, trying to socialize with the son she doesn't want, letting me curl up in bed with her again, planning fun family trips, etc.  Still telling me that there is "no reason to celebrate our anniversary, because there's nothing good about our marriage right now," but still open to doing something to mark the occasion, "if it makes you happy."  Still telling me that I don't do enough to support her opinions (I refer to them personally as marching orders, since disagreement, however minor, is cutting at her soul). 

In a relatively up moment like this, could this be the time to discuss separation?

[more background in intro post: https://bpdfamily.com/message_board/index.php?topic=272296.0 ]

[Turkish]

It sounds like you are at your wits end. How has it been going the last few days? How do you respond when she says stuff like that?

I never responded well myself, as I didn't want to deal with it. That, however, only drove her further away (abandonment behaviors).

[StrongDadOf2]

I am at wits end.  Our anniversary went better than expected, in that she did not break down and yell at me.  I took her out to a nice dinner alone and got her a present that I knew she had been wanting.  She was an emotional black hole and said, again, that she was just there because she knew it was important for me to celebrate our anniversary.  After dinner, she asked me, "Are you expecting me to feel guilty for not wanting to celebrate and not getting you anything?" to which I replied that I was happy to have been able to spend some alone time with her.  Since that night, she's been pissed off at me, but not telling me what is bothering her.  She's been mopey and snippy at everyone around the house, but I've stopped asking her what's bothering her.

Some good news is that my therapist, who works with our couple's therapist and my wife's personal therapist, confirmed in session that my wife does, most definitely, have BPD, and the reasons they cannot official diagnose her are to keep the family safe; telling her would set her off and she would completely leave therapy.  That knowledge helps me cope and lets me know that there are more people looking out for my family than I knew about before.