BOCA RATON, Fla. -- Former LSU cornerback Tyrann Mathieu says an October arrest for possession of marijuana is what enabled him to finally become honest with himself and turn a corner in his life.

Mathieu, who has been training for the NFL draft at a facility not far from where Monday's Discover BCS National Championship will be played, spoke with ESPN about his drug problem, self discovery and hitting rock bottom.

"Sitting in that jail cell, it clicked," an emotional Mathieu said. "Looking at those people, just staring at me. 'You don't belong in here.' They wanted to come through the jail cell and get me. I'm scared now. Because it's reality now. I don't ever want to feel like this again. I'm not going to feel like this again."

One year ago, Mathieu was a Heisman Trophy finalist, preparing for a national championship game. Since then everything has changed. In August he was dismissed from the LSU team for a failed drug test, and an arrest and a missed football season have followed.

Mathieu has many regrets. And he believes his poor performance in last year's BCS Championship Game was a factor in his marijuana issue.

Because last year's title game loss to Alabama was played in New Orleans -- near where he was raised -- Mathieu said he was distracted.

"I remember worrying about me playing in my hometown and showing up and damn, I don't think I'm going to show up," he said. "I hope I show up. I hope I have a game like I did against Georgia or Auburn. And it really took me out of my preparation for the game. I didn't give up a touchdown but I gave up four or five passes. Passes when I knew they were going to run that route. I mean, I knew they were going to run that route. But I didn't prepare myself. I was worried about everything outside the game."

If he had to do it over, Mathieu said, "I would have shut my phone off. I would have stayed in my hotel room."

Not staying at home is a mistake Mathieu, 20, says he's made too often.

It was in August when the immensely popular Mathieu -- nicknamed "The Honey Badger" because of an ultra-aggressive on-field demeanor overshadowing his 5-foot-9 stature -- was dismissed from the Tigers team because of failed drug tests.

"Devastating," Mathieu said, tears flowing. "It's all I had. Football. And to think back on it, as I told you, for the BCS game, I abused myself. I took it out on myself. So many people were trying to help me. Coach Miles, he was basically like my LSU father. And our head trainer, Shelly (Mullenix), was like my mother at LSU. Those people did everything for me. All they wanted was for Tyrann to make a play. They just wanted me to show up. I prepared myself so hard in the spring and summer just to let everyone down."

Mathieu said he used marijuana as a way to deal with problems on and off the field.

"I'd tell the world I abused myself though marijuana," Mathieu said. "I abused myself through marijuana. Was I addicted to it? Maybe. Did I form a habit of it? Yes. When people didn't think I had a good game or I didn't have the greatest practice ever, I didn't go into the office and try to figure out what was going on. I just automatically abused myself."

When Miles informed him in a 5:30 a.m. meeting that "you can't be a part of our family anymore" Mathieu said he began sobbing. He asked a school official to notify his parents because he couldn't bring himself to do it.