Who says Green Day isn’t punk rock anymore? After an EXTREMELY public drunken breakdown, Billie Joe Armstrong is showing that he still parties like a rock star. Unfortunately that partying has landed him in rehab.

The Time Of Your Life singer was on stage in Las Vegas at the iHeart Radio Music Festival when he freaked out after he thought he was being bumped for Usher (which festival representatives tell us was a scenario that was completely fabricated in his head). During the freak out he screamed profanities at the audience for a few minutes before bashing Justin Bieber and ended his hissy fit by smashing his guitar.

Yesterday morning, just one day after the meltdown, a rep for the band confirmed that Billie Joe has entered into rehab for substance abuse, which has forced Green Day to cancel all upcoming promotional appearances and shows. Shitty timing for a band who just released a three-part album!

We hope Billie Joe gets the help he needs.