Justin Bieber fights back against 'countless lies'

Justin Bieber's endlessly chronicled mishaps - from his birthday to his lateness to his scuffles with paparazzi - have caused more than one person to question whether the 19-year-old is at the start of a downward spiral.

But in a lengthy post on Instagram, Bieber's dismissing any notions that he'll be the next teen star to land in a rehabilitation facility.

"Everyone in my team has been telling me, 'keep the press happy,' but I'm tired of all the countless lies in the press right now. Saying I'm going to rehab and how my family is disappointed in me," Bieber wrote Thursday, ahead of a performance in Madrid.

"[I]f [a]nyone believes i need rehab that's their own stupidity lol I'm 19 with 5 number one albums, 19 and I've seen the whole world. 19 and I've accomplished more than I could've ever dreamed of."

Some people, he said, must find it "scary ... to think that this is just the beginning. I know my talent level and i know i got my head on straight. i know who i am and i know who i'm not ... My albums could be about anything but my messages have been to never say never and believe, not to believe in me but to believe in yourself ..[.] I honestly don't care if you don't believe in me because I believe in me, my friends believe, my family believe, my fans believe, and look where that's gotten me so far."

According to Biebs, he penned his Instagram'ed statement with "a smile" on his face and "love" in his heart.

"I'm a good person with a big heart. And don't think I deserve all this negative press," he concluded. "I've worked my a** off to get where I am and my hard work doesn't stop here... All this isn't easy. I get angry sometimes. I'm human. I'm gonna make mistakes. [I'm] gonna grow and get better from them."

Bieber originally tweeted a statement that included a diss to the actress whose name is so often brought up in these conversations, Lindsay Lohan. The first version, according to TMZ, said, "... to those comparing me to Lindsay Lohan look at her 2012 tax statements ;) "

But the singer told the site that he quickly deleted that initial commentary, and then published a revision.

"My post was only up for a few minutes but I realized right away that what I said at the end was wrong and distracted from what I was trying to say," he said. "I immediately deleted it and rewrote it so it would show what I was really feeling and those words are up now."