Where does the Bible say that those who go to "Hell" will be burning for eternity and not dying?

It's odd. I've been a devout Christian my whole life and have never actually studied Hell in the Bible. I BELIEVE the Bible is TRUTH, but I have also found that so much is misinterpreted, so I have gotten very in depth with my studies lately. So right now I am studying Hell, and have not yet been able to find where the Bible says those who go to Hell will burn forever. There is a scripture about the righteous walking over the ashes of the wicked, about how Sodom and Gomorrah is an example of what will happen to the wicked, of how the wages of sin is death, of how those who believe in Jesus "will not perish but have everlasting life"...the choices here are perish (die) or live...So I'm not trying to get into a big debate. I'm just a Bible believer and a truth seeker, so please feel free to present any further evidence on this topic from the Bible. Thank you!