Daily Star reports, The 22-year-old has teamed up with the UN Women movement to back their new HeForShe Arts Week in a bid to help bring about gender equality.
With around 40 events taking part across the capital over the next seven days, the programme hopes to make signifiant strides by battling gender stereotyping and sexism.
Opening up the campaign's launch in central London, James said: "When I was around the age of 15 I lost lot of my friends as they got into a grammar school and I didn't.
"I didn't know anyone at the school I was at, maybe three people.
"I lacked confidence, I had severe acne, I was overweight and I didn't really fit into any social groups."
Explaining how he turned to music, the star continued: "I started having a passion for music and luckily it was noticed by a few teachers.
"I nurtured it and I wrote songs in my room and I put them online."
However, his open lyrics and ability left him a sitting duck for bullies who singled him out.
"I was naive and didn't know what to expect but I was immediately victimised by people that I didn't know," James continued.
"Boys that I didn't know. Boys that were playing football.
"Going clubbing even through they were sixteen but they wanted to get into fights to show off their masculinity – for me I was in a dark place."
He added: "It is something that could have changed my life altogether.
"I was very close to putting down the guitar.
"I didn't know how bad it was – I didn't know why I was feeling like I was as for me music was my passion."
In James' case the bullies didn't win and he went on to join The Vamps with the foursome releasing their debut single Can We Dance in 2013.
The track reached number two in the charts with their second and third singles also landing in the top three in the UK charts.
However, many people growing up around the world aren't so lucky.
HeForShe week hopes to offer support to those in need and raise awareness of gender equality via the arts.