Not OP, but it happened to me. Started meditation to deal with anxiety and the introspection that came with it, ended up with me on the verge of a complete breakdown. I started off doing Sam Harris and then progressed to doing an hour or more each day. I had some moments of insight and then hit some dark night of the soul which wrecked me, I was close to admitting myself to hospital for psychological help.

What fixed me was finally reading Breath by James Nestor and how you breath has a direct impact on the parasympathetic / sympathetic nervous system. I learned to take long slow breaths into the diaphragm and too nose breath all of the time. Basically my vagus nerve was fried from burn out and being in the fight flight mode of the parasympathetic system, as opposed to the 'rest and digest' chilled nature of sympathetic nervous system.

My own view now, is that mediation should not be attempted (at least by anyone with mental issues) until the parasympathetic / sympathetic system is balanced and stress is significantly reduced. This should start with the breath.

https://www.vice.com/en/article/vbaedd/meditation-is-a-power...