And sadly the Blue crooner found himself in the firing line from cruel Twitter trolls who targeted his heritage – his mother is Jewish while his father is Greek Cypriot.
Yet the slurs taught Antony a lesson in not rising to the venom – of which he has a few pearls of wisdom for spat king James Arthur.
Chatting ahead of The Big Reunion 2 tour kick-starting in late autumn, the 32-year-old warned the X Factor motormouth to “not believe your own hype”.
Antony explained: “No one prepares you for the other side of fame.
“When you start, you just see bright lights, performing, stages – you don’t know about interviews, the papers, it’s just doing what you love doing.
“If people take an interest and start writing about you, great. If it’s bad, you’ve got to deal with it.
“Social media has changed a lot since we started, there was no Myspace, Yourspace, Anyotherspace, Twitter, so for us it was more anonymous. More of a secret.”
He confided: “It freaks me out when people record us at gigs on their phones because then you start becoming obsessed with yourself.”
When asked what advice he has for Recovery singer Arthur – who has had very public squabbles with Frankie Boyle, Lucy Spraggan and Teddy Edwardes – Costa said: “I’d say ‘Keep doing what you’re doing because you’re obviously a great artist, just don’t believe your own hype.’
“He’s got to know what he’s doing, he’s in his mid-twenties. I get it all the time, I’ve had anti-Semitic comments, ‘Jewish c***’ and ‘I hope your mum dies’, everyone’s got an opinion now.
“People just go on Twitter and tell you you’re a p****, and you’re like, ‘Okay, cheers.’
“But if I’m having a bad day, I don’t express it online, because whose business is it? You’ve got to deal with it yourself.”
Joking – or maybe not? – Antony quipped: “You never know, I might run for Prime Minister.”
“You start going into yourself, then you don’t want to speak and tell the other lads to talk in interviews, then you get blanked as you’re so quiet. It was hard to take. I became very introverted.
“But then I went on to do I’m A Celebrity [in 2005] after Blue called it a day, and that was the making of me. I found myself, I hate saying that, but I did.
“At first I didn’t want to do it, I told my agent, ‘I don’t want people hating me.’ I’m not a hateful guy, I’m just me. I seem reserved, but that’s not the case, once you know me I’m everyone’s mate.”
Antony’s confidence grew following his return from the jungle, confessing “it was a nice little ego boost, proving I could do something for myself”.
He added: “I’d have taxi driver’s beep me, saying ‘I f***ing hate the band, but you’re wicked.'”
In contrast, Big Reunion co-star Sean Conlon claims he never watches Five videos online, and revealed he hasn’t even watched the BAFTA-nominated ITV2 show.
“When I was 17, I’d meet all these famous people, and think, ‘How does a famous person act? If I’m normal I’m going to let people down. How do you act like a star?’ You get all confused.
“Sure, you’ve got to have some ego, when I started I was very self-centred, I thought the world was about me like every other artist, but having a family chills out you a bit.”
And the Leeds lad also had some personal insight to offer to Arthur, warning: “My advice would be, enjoy it while it lasts. It’s probably not going to last forever.
“If you can’t afford it, don’t buy it. You don’t have to always live up to what people expect, you’ll end up on your a***. Champagne taste, lemonade money.”
Meanwhile, refreshingly down-to-earth and likeable Antony believes there’s longevity in the franchise, saying if the series runs out of bands, it could invite solo artists onto the show.
He said: “I think it’s a genius idea, and if I wasn’t a part of it, I’d still be a genuine fan regardless.
“ITV and the team have definitely got something good going on.”
In the meantime, see ya down the front row in October…
17: Sheffield, Motorpoint Arena
18: London, The O2
19: Nottingham, Capital FM Arena
20: Cardiff, Motorpoint Arena
21: Birmingham, LG Arena
22: Bournemouth, BIC
23: Brighton, The Brighton Centre
25: Glasgow, The SSE Hydro
26: Manchester, Phones 4U Arena
27: Leeds, First Direct Arena
28: Liverpool, Echo Arena
29: Aberdeen, AECC GE Oil & Gas Arena
30: Newcastle, Metro Radio Arena
November
1: Belfast, Odyssey Arena
2: Dublin, The O2 Dublin Arena
Daily Star