I feel sorry for the kid and think it's quite odd so many adults have such venom for him and feel so much glee to witness a 19 year old boy having a meltdown. Say a lot more about them than it does about him. He needs some better quality friends around him and some time out of the spotlight. Sadly he's a cash cow for too many people so they won't allow him.
He is also very talented but the direction his management have taken him in doesn't really showcase it. Shame. He would have been better off forming a band with some friends and having a more low key career.
He wouldn't have had this reaction from people if it wasn't for him behaving like a two-year-old throwing a tantrum when he doesn't get his own way. He is very lucky indeed to have had any fame, given his lack of talent. He doesn't need to let his young fans down with no explanation, throw strops and fake illness to get publicity. What he needs is to take a long, hard look at himself and realise that he isn't a child anymore, and behave accordingly. The exemplary behaviour of most young people in showbiz should tell him that much - and making excuses for him just makes spoilt kids like him much worse.