Back in the '80s, George Michael seemed to be everywhere, but friends say now it would be hard-pressed to find him anywhere except his North London mansion.

Insiders tell the London newspaper The Mirror that the former Wham! front man has become a recluse, and hasn’t been out of his home since May, when he was hospitalized after mysteriously collapsing.  “People are worried sick about him,” said a source. “He’s just cut himself off from everyone.”

Of course, Michael has had some tough times recently. In 2010 he crashed his car into a store because he was high on pot, and was jailed for four weeks.  In 2011 he almost died from pneumonia and then last year he mysteriously fell out of a moving car, and had to be airlifted to a hospital with a head injury.

One source blames all of Michael’s problems on his 2009 split from his boyfriend-of-15-years, Kenny Goss.  “Since splitting from Kenny and all his problems, he’s just gone off the radar,” claimed an insider.  “It was really down to Kenny that he was actually out socializing – even if it was just going to the cinema locally or for a meal. He hasn’t been seen out for months, he’s self-conscious about the scars on his throat and head, caused by the M1 incident, and he’s put on weight.”

As for what he’s doing, an insider claims Michael’s been holed up watching DVDs and recording music in his own studio, although the insider adds, “It’s not good, creative or healthy.”