Justin Bieber gets nervous being "vulnerable" online.

The 31-year-old pop star has been candid with fans about his emotional state of late and now he has admitted mean comments get to him.

During a recent Twitch session, he said: "Going on Twitch is vulnerable as hell because people who just feel s****y about themselves project and then they write mean-a** things.

"It's already hard enough to put yourself out there, and then you gotta read all this."

The Sorry hitmaker even starts questioning whether the things people are saying about him are true.

He said: "They were like 'Justin is not as exuberant. He will never be his exuberant self ever again. He's lost his charisma.' I was like, 'What? I just played basketball last night, I'm just tired.'"

He went on: "And we're talking about emotional things.

"And I start getting in my head, like 'Ma, did I lose my charisma? My exuberance?' I have a zest for life … It just sucks that you can have a million people say the nicest thing and then the one comment gets in there."

Last month, Justin insisted he doesn't need "healing" after his mother's emotional post.

The 31-year-old singer responded to a lengthy and heartfelt Instagram post from his mother Pattie Mallette who revealed she is always "cheering" and "praying" for her son.

On September 22, she wrote: "We're cheering you on and praying for you always justin.

"I declare freedom, strength, clarity, and healing over you Justin. Every chain of fear, confusion, heaviness, and pain-- be broken in Jesus' name.

"Holy Spirit, surround him with TRUTH, LIGHT, and PROTECTION. HEAL EVERY WOUND in his heart, mind and body, seen and unseen, restore what's been stolen, and cover him in WHOLENESS.

"Fill him to OVERFLOWING with Your LOVE and COMFORT. Continue to raise him up as a voice for Your Kingdom, unshaken and on fire for You Lord.

"Silence every voice that doesn't come from You, and let his life be a bold witness of Your power, love, and healing grace. Say amen if you agree. (sic)"

A couple of weeks later, Justin responded in the comments under the post, dismissing the concerns.

He quipped: "Only thing I need healing from is my rolled pinky toe from playing ping pong."

It's still not clear what Pattie was referring to in her original post.

Over the summer, the pop star discussed his faith, and revealed he "wouldn't be able" to get through the day without love from Jesus.

Justin - who is married to model Hailey Bieber, 28, with whom he has 14-months-old son Jack Blues - wrote on Instagram: "Grateful for a new day. Grateful for Jesus...

"He meets me every morning with forgiveness and love that I truly don't deserve...

"So grateful that he gives this love so freely, so graciously...

"Wouldn't be able to get thru the day without his love. It meets me at my lowest. (sic)"