Shayne Corson woke up in the middle of the night in the summer of 2000 — thought he was having a heart attack, honestly believed he was dying.

“I was sweating,” the former NHL player said. “I was shaking. I got down on my hands and knees beside the bed and I start saying goodbye to everybody in my mind. I’m thinking ‘I’m dying right now. This is it.’

“That was the first time it ever happened. It didn’t really hit me until I was trying to decide whether to stay in Montreal or play for the Leafs. I was a free agent. I was torn. I didn’t say anything to anybody. How do you explain that? My dad died at 45 and I’ve always been afraid of dying young. I think about that a lot. And then this happens and you’re trying to figure out — what’s going on with me? Why is this happening to me?”

For almost his entire NHL career, the 19 years, the 1,156 games for five different teams, Corson kept his anxiety problem to himself. His coaches didn’t know. His general managers didn’t know. His agent didn’t really know. The odd teammate, the close ones, knew, and his mom knew, and maybe a few family members.

“I was afraid to tell anyone,” said Corson. “I was afraid and embarrassed to show weakness. I probably should have opened up to someone like (Pat Quinn). He was the kind of guy who would have understood. I probably should have told people. I can see that now. I couldn’t see it then. If you’re trying to figure out what’s wrong with you, how can you expect others to understand?”

Corson saw Roberto Osuna on television not long ago, read the words of the Blue Jays closer, heard about the young man going public about his problems with anxiety. He heard it and wanted to reach through his television set to tell him he understands. He wanted to tell him how proud he was that Osuna, at age 22, had the courage to tell the world he was hurting and needed some help and understanding.

“My instant reaction was, ‘I know exactly what you’re going through, man,’” Corson said in a lengthy interview. “I’m glad he came out with it. I’m glad he had that courage to do that. I tried to deal with it on my own. I wasn’t very successful. You get to a point where you’re kind of living in a dark hole and you can’t climb out of it. It takes over your mind. It takes over your body, sometimes.

“If Roberto wants to talk about this in any way, tell him I’m available. If I can help, I will. I’ll be honest, I know how much I suffered. And if I can help one person not go through what I went through, I’m there. This is something we need to talk more about. So many people have it.

“(Bad) stuff would cross my mind and I had to turn the switch and say no. Keep battling. Keep fighting. You think of your mom. You think of your sisters. I’m not ashamed of what I’ve been through. It’s taken me a long time to be able to talk about it.”

Corson understood injuries. A knee injury, six to eight weeks. A shoulder injury, several months. “There’s no time frame on anxiety,” he said. “You don’t know if it’s ever going to end. You don’t know if you’re going to get out of it, or how you’re going to get out of it. Some days, it’s almost like you want to rip your skin off. I’d start pacing. You want to get out of your body but you don’t know how. Your heart starts racing. You feel like your organs are shutting down. I’ve been to emergency a bunch of times over the years. You think you’re dying.

“One time, I stayed awake for 12 straight nights during training camp. I couldn’t sleep and I couldn’t stand being awake. It took over my life. I started medicating myself. At first, it was one Ativan. Then I was taking a stupid amount of Ativan. Just to get through the day. At one time, I got down to like 189 pounds. I played most of my career over 200 pounds. Things just spiraled in the wrong direction It just got worse and worse.”

During the 2003 Stanley Cup playoffs, in his second last season, he walked out on the Maple Leafs in the midst of a series in which he wasn’t dressing for games. At the time, it was a significant story, an apparent split in the dressing room. The reporters covering the Leafs knew nothing of his anxiety issues.

“I had to go,” he said. “Put it this way, I had to.”

Post career, Corson went through a variety of doctors through the NHL Players’ Association, who tried to help him get his life under control. “As soon as I admitted to people what was going on, I felt better,” said Corson. “Talking about it is really important. That’s why I’m proud of Osuna. He’s dealing with it right away. I’m happy for him.”

Life remains a challenge for Corson. He still doesn’t sleep well. He still has panic attacks. He still wishes he could make this all go away.

“Talking about it matters,” he said. “People I know come up to me and say ‘I didn’t know you had this, I have that.’ You start talking. You find out others struggle too. You can be having a great career (like Osuna) but you don’t know what anyone is feeling inside. Nobody really knew what I was I feeling. My dad died at 45. I’m 50. He fought his ass off to keep living. I’ve done the same.”

[Steve Simmons is the national sports columnist for Postmedia. He can be reached at ssimmons@postmedia.com or twitter.com/simmonssteve]