Martin also spoke about his split with Gwyenth Paltrow.
The couple ended their marriage last month, announcing they were "consciously uncoupling" via Paltrow's Goop website.
At the time, Paltrow and Martin insisted their split wasn't acrimonious.
But Martin opened up in the interview.
"I wouldn't use the word 'breakdown' - this was more a realisation about trying to grow up, basically," he told Lowe, according to UK newspaper The Sun.
"If you can't open yourself up, you can't appreciate the wonder inside. So you can be with someone very wonderful but because of your own issues, you can't let that be celebrated in the right way."
The singer says he hasn't been in a good place for a few years and his personal fears got in the way of his happiness.
"What changed for me was that I don't want to go through life being scared of it, being scared of love, being scared of rejection, being scared of failure," he said.
"Ever since our band came out, we have been a very polarising group because we do a certain thing very well. About two years ago I was a mess, really, because I can't enjoy the thing that we are good at and I can't enjoy the great things around me because I'm burdened by this.
"I've got to not blame anyone else and make some changes."
Meanwhile, Coldplay have sent fans on a global treasure hunt through books of ghost stories in a bid to win concert tickets.
The band has hidden lyric sheets handwritten by Martin in books of creepy tales in libraries in nine different countries.
Fans will have to decipher clues given on Coldplay's Twitter page to track down the books and lyric sheets.
The news was announced on the band's official webpage.
"The band have decided to reveal the lyrics for all nine songs from the upcoming Ghost Stories album by hiding Chris' handwritten lyric sheets in libraries worldwide.
"The lyrics will be hidden in ghost story books in libraries in nine countries, located across the planet.
"Clues to the exact locations of the lyrics will be posted from today on the band's Twitter account ... using the hashtag #lyricshunt.''
One of the hidden envelopes will contain a special golden ticket granting the winner a trip to London to see the band perform on July 1.
- WENN and Bang! Showbiz