Plastic surgery king Michael Jackson came completely unglued at the MTV Music Video Awards — suffering a severe panic attack before his horrified handlers forced him to go onstage.

“Michael was completely unhinged,” revealed an MTV insider at the star-studded event in Manhattan’s Radio City Music Hall. “I knew he was weird but this was scary!

“We were on our way to the stage, where he was to join Britney Spears as a presenter, when he just snapped.

“Michael started waving his hands in the air above his head and started repeating over and over again, ‘There’s too many people! There’s too many people!’

“He suddenly stopped short and he got this frightened look in his eyes. I thought for sure Michael was going to turn around and run.

But a show staffer insisted the Gloved One fulfill his commitment. Michael nodded and walked onstage like nothing had happened.

But things went downhill from there. Bouncy Britney gave him a birthday cake because it was his 44th birthday and remarked that she felt Michael was the Artist of the Millennium. Wacko Jacko thought she was giving him an official award with that title — and made a speech accepting it.

The host Jimmy Fallon joked that they were giving those awards to everyone.

“I heard him squeal in his high-pitched voice, ‘ I won’t be made fun of like this!’ ” said the insider.

An MTV exec said:

“Michael acts as if he’s King of the Hill — when he’s really over the hill.”