Ridiculous ebonic slang gone overboard. A mutation of a mutation. i.e. "off the hook" and all of the -izzle nonsense combined to make a new and extraordinarily retarded phrase.
A mild example of this sort of double mutation would be like coining the word "Wazzigga" to mean "Whazzup, Nigga?"
Dumbass1: Yo, Wazzigga!?
(Hello there. What is up, my friend?)
Dumbass2: You're Off the Heezie Phascheezie!
(I love you.)
"During the party last night, Jake was totally off the heezay. He kept rambling about conspiracy theories and dancing wildly, completely oblivious to everyone else around him."