But your link gives two senses, and it's the second one that applies here: "Used as an intensifier with statements or terms that are in fact meant figuratively and not word for word as stated". And Wiktionary offers the synonyms virtually and so to speak.
"it hurts so bad I’m intensely dying" would be wrong too. It's more than an intensifier, it also means "figuratively".
> Used as an intensifier with statements or terms that are in fact meant figuratively and not word for word as stated
That is not the same as the meaning of “figuratively”!
“‘Literally’ is used with statements that are meant figuratively” does not mean the same thing as “‘Literally’ means ‘figuratively’”.
> "it hurts so bad I’m intensely dying" would be wrong too
Indeed, because “intensely” is not an intensifier. In your example, “intensely” modifies “dying”, whereas “literally” modifies the tone of your utterance.
For an example of another intensifier: “it hurts so bad I’m fucking dying” would work.
Nobody would claim that “fucking” means the same thing as “figuratively” in this sentence, even though the sentence is itself figurative.
> It's more than an intensifier, it also means "figuratively".
No, its an intensifier for things which are contextually unambiguously figurative. It doesn't communicate that the use is figurative, it communicates intensity. The figurative nature of the expression is understood from context, not the use of the word "literally".