To give an indication about their success story, their first album managed to reach the top five in the US and UK and their 2012 BGT audition got nearly 40 million YouTube hits.
Jonathan bared his heart to the Sunday People about the immense problems he underwent in the initial years when he was dating a girl.
Jonathan confessed to being so depressed that he attempted self-harm by cutting his stomach after he was dumped by a girlfriend who self-harmed obsessively. He explained that his relationship with this girl was so negative that it changed him completely from being a happy teenager to one who lost the zest for life.
He said: "She was pretty messed up. She was self-harming a lot. I tried to hide it from mum because I knew she'd be really upset. But my girlfriend didn't really care about being discreet. She would cut herself in front of me. She'd take blades from pencil sharpeners and cut herself ≠upstairs in my bedroom when mum was at home downstairs."
"I hated it. I spent all my time hiding blades and sharp things but she would have cuts all over ≠herself and wear clothes so you could see. So my mum found out and that was really stressful."
Jonathan was madly in love with this girl. He said, "She was all I thought about. She got moved to another school and then later moved out of the area. I got a phone call from her saying we were over. That was it. She hated me. It all ended in a phone call. I lost it. I told mum and then I went upstairs. I removed a blade from a sharpener and cut up my torso. There was blood ≠everywhere. My mum walked in and just went into meltdown."
"It was like everything in my head just exploded. I don't know why I cut myself when I knew it was a crazy thing to do but I just wanted to hurt myself."
Things changed after he met Charlotte. From then, it was a miraculous journey of signing up for auditions, losing weight and doing something fruitful and positive in life.
He said: "I've always been big. I used not to care, even though I did get bullied. But now I want to be healthy. I don't want to die. I want to be around to enjoy this. I want to sort myself out."
"It's like I've got another life and I love it. I never expected things to turn out this way. What was the nightmare ≠became the dream. If anyone is proof that you can go through the worst stuff and come out the other end, it's me."