Diddy Hospitalized

Diddy was hospitalized this AM for an extreme migraine ... TMZ has learned.

The mogul hosted a post-Grammy party at the Playboy Mansion Sunday night (below). After the party, Diddy went home and got a massive headache.

Diddy's entourage became so concerned ... they drove him to the UCLA  emergency room -- btw, the same place where Michael Jackson was pronounced dead.

Diddy was treated and is back at home ... feeling a lot better. A Diddy source tells us ... the migraine was unrelated to anything that went down at the Mansion.