If I have a huge disadvantage against someone, should I just resign?

You can always win if they blunder badly or run out of time. Just play through the end unless it really clear youre losing

Just play till the end, there is a chance of opponents making some mistakes.

"Nobody ever won a game by resigning"-ummm, who the heck said that?

If you have a huge disadvantage at a low level, you should play on, as there is a good chance that the opponent blunders. However at a higher level you should just resign, as there is basically no point in continuing, but if its not too bad you can still win

yes

chess is about getting better as fast as possible. you can play a new game.

Resign

and analyze how you got into this bad position.

Who else can say? You should resign when you have no more hope, and you are the only person who knows when that is. Even hope based on ignorance is reason enough to play on. That's one of the great things about chess. You alone are responsible for your choices, including whether and when to resign.