The description of feeling like he was "in a coma or some afterlife limbo state" sounds similar to Cotard's syndrome [1], a very rare condition that can develop

The description of feeling like he was "in a coma or some afterlife limbo state" sounds similar to Cotard's syndrome [1], a very rare condition that can develop from untreated schizophrenia — basically an unshakable belief that you are, in fact, dead, and every other fact of existence will have to be reframed to support that belief. [1] https://en.wikipedia.org/wiki/Cotard%27s_syndrome https://en.wikipedia.org/wiki/Cotard%27s_syndrome