Paralympics 2016: US sprinter Patrick Blake Leeper vows Rio ban won't 'break him'

hate the fact that I have to sit here today and have this conversation with you. I wish it was a conversation about the times I'm running or what time I'm going to win the gold medal in."

American star sprinter Patrick Blake Leeper wishes he were in Rio de Janiero right now, participating in the 2016 Paralympics. Instead, he's speaking to CNN from his home in Los Angeles, after losing an appeal to the Court of Arbitration (CAS) for Sport last month.

In 2012, the American, medaled twice at the Paralympic Games in London. He earned a bronze for the 200 meters race and a silver medal for the 400m, seconds behind South Africa's Oscar Pistorius.

He vividly remembers how he found out he would not get his chance to shine four years on.

"I was doing relay practice, ready to take the anchor leg ... practising how I was going to break Oscar's world record in the 400m then I got a phone call to say 'sorry but you're not going,'" Leeper told CNN.

"Oh my God that hurt. I didn't know what to do. For two days straight I can't sleep, I can't eat. It's all like a bad dream again."

In 2010, while a student at the University of Tennessee, Leeper decided to try out for track and field running with the prosthetics.

He instantly impressed and was persuaded to leave home to train at the Olympic Center in California. His success in London was life changing.

He'd travelled there as the "disabled kid from Tennessee not knowing what the future holds." On his return to the US, Leeper was given the keys to his hometown of Kingsport, appeared on TV shows and played in an NBA All-Star celebrity match.

"It came fast for me," he explains. "It came extremely fast.

He might have been a professional athlete but he was also now very much a public figure, and learning how to deal with those new responsibilities.

"You have to be a role model, to show up at events, to sign autographs because you never know what individual needs to hear your story to stay motivated."

Increasingly he found it difficult to meet the demands of what was being asked of him.

"As more good things happened in my life a lot of pressure came with that so my drinking increased. Unfortunately I didn't have the tools to be able to cope with the situation."ven before he went to London in 2012, Leeper had a drinking problem. In 2011, he was suspended from competition for three weeks for alcohol abuse.

"I started drinking at an early age," he explains. "But when you're living a normal life as a college student it doesn't seem out of control."

Fast forward to June 21, 2015, when the sprinter tested positive for benzoylecgonine, a metabolite of cocaine, during the US Paralympic Track and Field National Championships.

"Patrick is an alcoholic," Leeper's lawyer Matthew Lewis tells CNN. "While inebriated, he took a recreational non-performance enhancing drug approximately one week before a competition."