"I thought I could bet on sports with my sports knowledge and win the money, but I found out that wasn't the case," he said.
At first, Ryan says he just wanted to make up for money he had made in past summers as a camp counselor. But after using a credit card to place his first wager of $500 and losing, Ryan didn't stop betting -- he did more of it.
"My recourse was to bet again -- $500 and get even," Ryan said. "So I bet $1,000 on a game and then I'm down $2,000. The I was starting to get worried."
Before he knew it, Ryan says he was $20,000 in debt. But it wasn't the depth of the hole he'd dug that scared him, it was his reaction to it.
"I can't pinpoint it exactly, but I had a strong sense that I was out of control," he said. "My reason to get out of the hole was to bet more -- it wasn't to stop and find help."
Ryan finally came clean, graduated from an Ivy League college and now helps counsel other young gambling addicts.
He says the key to overcoming a gambling addiction is honesty -- with yourself.
"Not just with other people, but with yourself," he said, "and to know that to ask for help is not a problem ... it's not a weakness. To ask for help is a tremendous strength."
Sarah Wallace, of ABC News affiliate WABC, contributed to this report.