The teen popstar was at the centre of a media storm last year when Yeater claimed that he was the father of her child.
"At the beginning of it all I was in Florida, away from my friends and family and I was pretty sad," Bieber told Fabulous.
"I got to the point where I thought, 'I don't want to do this. I just want to be normal'. It was difficult because I'd never gone through anything like that."
He added: "Usher was like, 'Prepare to have this for the rest of your career because it's not going to stop'.
"He's gone through some stuff and most artists go through their fair share of bull. That was just my first time."
Asked how he felt about Yeater, he added: "I feel sorry for her more than anything.
"Everything that hurts you makes you stronger in the end. You've got to learn from the bad things that happen."
The full interview can be read in this Sunday's Fabulous magazine free with the Sun on Sunday.
Watch the video for Justin Bieber's 'Boyfriend' below: