My take on this has oscillated throughout the path. Initially when I came across the notion of a dark night yogi, I thought it explained all my troubles. I probably could have earned a mood disorder diagnosis, and I have mixed feelings as to whether or not I'd have been better off going that route at certain points. The tipping point should probably be suicidal ideation. That's when you need someone else supervising your decisions.
After first path, my perspective changed. I thought, the dark night wasn't so bad in the context of practice, and probably had nothing, or not everything, to do with previous years of depression. And now, a couple paths later, baseline happiness is much happier. When I experience a dark night cycle, it's such a stark contrast. It comes out of nowhere, this sense that life just sucks, and then poof! Gone. For a moment, or a day or two, it was like the old days. So, maybe it really was the dark night all along.
At the moment, given the season and certain rather extreme financial pressures, I should be terrified and miserable by the standard of the past. And I just can't be bothered about it that much. I take care of business and forget about it. I don't think it's A+P or mania, or even EQ especially. If I'd had this perspective ten years ago, my whole life would have been different. Oh, I could nurture a few regrets. But I just can't be bothered. Everything is okay.
I tried and tried to meditate my way through but there was almost zero concentration.
I think that's pretty normal in DN stages. Sometimes I just let it wash over me like a bad acid trip. Even if you can't note. Let your mind torture you. surrender. If nothing else, you start to see that it is just mind, it isn't self and it doesn't last. But don't push too hard, don't expect progress. One day soon it will just come. You'll sit through hell and then the last 2 minutes feel calm. And the next day five minutes. And then 10, but the hell was a bit cooler. And so on.
During the DN stages before 1st path I did a lot of vegging out. It's not a wholesome suggestion, but probably a lot less detrimental than drinking, which will make you feel worse.
Hope that helps. Good luck.