I think went through the Dark Night of the Soul a few weeks ago. It lasted three days. I got out of it I got out suddenly, via insight. Whatever the experience was, it changed me.
The Dark Night was an awful three days. I escaped by letting go of the idea I should be something other than what I am. I know people who would not do the same. They might be stuck in the Dark Night for a long time.
Most of my life I had two separate ideas in my head: the person I am and the person I should be. The person I should be was like me except fitter, smarter, etcetera. I tried to become the person I thought I should be.
I got out of the Dark Night by letting go of the idea there is a person I should be. The concept there is someone I should be no longer makes sense to me except as an evolutionary hack like anger. I have gotten over it.
The idea there is someone I should be was a common source of dukkha for me. No longer.