I have. It definitely isn't. It may have been exacerbated by biochemical causes, but it wasn't caused by them alone. (Sertraline did help me, just never as much as nullifying an existential problem.)

Sertraline has insomnia listed as a very common (>10%) side effect. If you're currently on it, this is a more parsimonious explanation for your difficulty sleeping than your philosophical beliefs about how sleeping interacts with subjective experience.