The question Fuzzybear brought up is what's also on my mind. There could be more at work there than 'just' depression (which can be so devastating , of course, even on its own). The out-sized anger and defensiveness, along with personally attacking you, feel like guideposts toward multiple issues being in play. This is especially true as you are certain that, normally, she is a very good person, and that these behaviours are uncharacteristic for her.

I have gone back, and read some of your earlier posts about your wife's treatment of you. I am not an expert, but the way she talks to you, so aggressively and dismissively, is reminscent of a close relative of my husband's, who I believe is struggling with a form of Depression, along with a type of Borderline Personality Disorder of one kind or another. There are also several other options---I'm not a diagnostician, but a couple of possibilities spring to mind.

I don't know of many people with Major Depression who would also be so routinely ungrateful as your wife sounds, given what you actually do for your entire family. Most people with MD would think themselves very lucky to have another, significant other who cares and is as patient as you have been. It is unlikely they would be regularly abusing the person that's doing so much to help them. That does make me think there's something else at work. And, don't get me wrong---I know she is suffering. But it does not, and never will give her permission to belittle or berate you, or to be dismissive or cruel towards you. You seem like a pretty caring and concerned individual. You've hung in there with her through an awful lot, and do seem to be trying very hard to understand her predicament.

It's good that you've been taking better care of your own mental health, and treating your anxiety.

It's completely possible your wife might also need a med change (I didn't read everything you've written, so forgive me if I missed something, there), or some intensive therapy. I saw she displays no interest in counselling, but perhaps you could benefit from speaking with someone. Very often, the caregiver in many situations needs just as much help as the sufferer---just in different ways.

You should print out copies of your posts here and perhaps create some sort of timeline to take with you to a qualified doctor. Patterns of behaviour over time can assist greatly in reaching a more complex diagnosis quickly and accurately.

My heart goes out to both of you. You do strike me as a loving and supportive husband.

I wish you both better days & nights, as well as answers.