It’s never wise to ask for something conclusive regarding religion.
I would like your personal views, and what your religions teach.
On the two specific answers, would I know I’ve been separated from God? The ceasing to exist part doesn’t sound like hell, it sounds like the most likely thing that happens to everyone that dies, so that’s a strange way to look at hell IMO.
I don’t belong to a religion fwiw. If one believes in souls and God, ceasing to exist = destruction and not something that happens as a matter of course to everybody. Between eternal paradise and ceasing to exist, it seems a great punishment.
Being separated from God would entail knowledge of it. Spending eternity with no meaning and no escape.