I'm sure that's a lesson you won't soon forget. Alcohol tends to do that (no, that doesn't mean the way to treat a high is with vodka!). But if that was yesterday, and you've got bad rebound highs today, that means you made it through and things could've been much worse than they are.
As for the final two words of your post... no, it's not The End. You're still here. Thank goodness for that!