Justin Bieber has confessed he isn't in the 'happiest place' since splitting from Selena Gomez earlier this month.The 'Boyfriend' singer - who split from his on/off girlfriend Selena Gomez earlier this month after two years together - has revealed he isn't dealing with their split very well and is still heartbroken.In a new interview with Billboard magazine, set to be released on Monday (28.01.13), the 18-year-old Canadian singer said: "I'm not in the happiest place that I've ever been."Justin tweeted a photo of his cover for the music magazine on Friday night (25.01.13) with the caption "tried to be honest".The interview comes ahead of the release of his new album 'Believe Acoustic' on Tuesday (29.01.13), which is said to include lots of songs about the couple's break-up.Justin is said to be desperate to win Selena, 20, back and was recently said to be trying to act more mature so she can see he has changed.However, Selena has reportedly moved on after telling friends that Justin was too needy for her.A source said: "Justin is super needy and can be a big baby around Selena. It's hard for him to make real friends because he likes the temporary attention of strangers, but didn't see how it hurt Selena."Selena didn't feel Justin was respectful of their relationship. She was constantly catching him in positions with other girls that would make her uncomfortable. She would get super jealous."The couple broke up shortly after holidaying in Mexico where they had planned to ring in the New Year together but got into a huge argument on December 30 after she allegedly found text messages from other girls on his phone.