British pop star Matt Cardle has opened up about how his addiction issues left him weeks from death before he entered rehab last year (13). The singer, who won Britain's The X Factor in 2010, checked into London clinic The Priory on 29 December (13) to reportedly tackle an addiction to prescription pills. He subsequently cancelled a string of shows to focus on his recovery, and now he admits he was taking huge quantities of anti-anxiety drug Valium before his brother urged him to seek help over the Christmas holidays. Cardle tells The Sun on Sunday, "I was so out of it - I was like a zombie. The doctor said to me if I'd been left to my own devices for another three or four weeks I might not be here now. "I didn't have my wits about me to even count how many I'd taken. It was a lethal situation. Towards the end I was so out of it I was asking people around me how many pills they'd seen me eat. "That is what kills people. It's what killed Heath Ledger and Anna Nicole Smith. Any time I started to feel stressed I would lean on the drugs and drink. "I was kidding myself thinking I had a handle on it. That little word in front of the drug 'prescription' gave it an air of safety for me. "But it's the total opposite - they are so highly addictive both physically and mentally." The 30 year old is now gearing up to a U.K. tour in April (14) and is determined to give fans his best as a thank you for their continued support. He adds, "My fans have been so great - I just want to be able to go out and give it 150 per cent for them. I am completely sober for the first time in a long time - and I feel brilliant."