Diddy Apologizes -- 'I'm Sorry for the Ignorant Way I Represented Myself'

Diddy claims he "backslid and regressed" when he shouted racial and homophobic slurs at a clubgoer in Atlanta this weekend ... and now the rap mogul is begging for forgiveness.

Diddy went to his Twitter page a few hours ago ... and issued an apology to his fans for the way he acted inside Compound nightclub Saturday night ... when he threw ice at a clubgoer, threatened to fight the guy ... and then called him a "n**ga" and a "f**got."

Diddy explained, "I'm sorry for the ignorant way I repesented [SIC] myself ... I have backslid and regressed. Forgive me for my ignorance. Pray for me pls. I know better and I am better."

He added, "I have a responibility [SIC] that I promise I will live up to. And I'm more dissapointed [SIC] in myself than you know. I will humble myself and learn."

TMZ spoke to the man on the receiving end of the slurs, Ricky Parker, who tells us he felt "humiliated and disrespected" by Diddy ... and claims he will no longer support the hip hop icon.

Parker tells us he couldn't believe that Diddy would attack him so ferociously, simply because he was drinking Grey Goose vodka that night and NOT Ciroc vodka, which Diddy serves as a spokesperson for.

Parker tells us, "You won't ever hear me support him from this moment forward."