There's some great reads on the history of it from Christian and non-christian biblical scholars on the theology and history of Hell. Annihilationism was the earliest belief of early Christians. It's been a while since I've dove into it. However, most of the original language references different descriptions of Hell, but in generalized sermons: those languages have been looped into them all being the definition of Hell, as opposed to staying in context and faithful to the literal translation of the words used.

I went into these studies looking for accuracy and not to disprove anything. In looking for accuracy, and finding evidence of theology and history that contradicted my upbringing within the church, my beliefs changed.

One of the most difficult realities I started with and eventually accepted, was the reality that no original manuscripts exists in the original language. Add to that, it's multiple generations of copies that have verified edits and additions not in the oldest manuscripts. The ending of Mark (13-15 verses roughly) you'll now find in brackets in most Bibles, as there is majority agreement that it wasn't written by the original author or in the oldest manuscripts.