I've been married 20+ years and my Mrs still throws back stuff that happened before I met her - it's fricking annoying, but I guess she just wants to feel secure sometimes.
But what you are going through is beyond that, she's up all night and sleeping all day? What is she doing during these times?
I have a mate who went through the same thing, he was working, looking after the kids, cooking, cleaning etc - she didn't work, so anything around the house and was in bed most of the day.
It effected his mental health, his job and he eventually, and we're talking years, left her. She moved back to her home town, where she had to work and she eventually started getting help.
They reconciled earlier this year and he says the marriage isn't without its issues, but she realised she had/has mental health issues and it took a sharp reality check and a therapist.
I'm by no means saying leave your wife, just that what is happening now, is never going to get better on its own - she needs help and she has to have her own lightbulb moment and want that help. Much like an alcoholic, you can't help them unless they want to get clean.
Personally, if she was prepared to get help, I'd stick around, but if she wasn't, it would be time to call an end and start looking after yourself and the kids will being.