The 34-year-old said the support he had received from his wife Paulina, sons Kristiyan and Stiliyan and other relatives had sustained him through his treatment for leukemia.
Petrov announced his retirement in May as he continues his cancer fight.
He set up a foundation to help those affected by leukemia and said his priority would be to help other families stay together.
The Bulgarian, who also played for CSKA Sofia and Aston Villa, revealed he had already helped arrange accommodation for the family of a three-year-old undergoing cancer treatment at Yorkhill Hospital For Sick Children in Glasgow.
He said: "I can see the smiles on the faces because they can be close to their children.
I realise how important it is for close family to be around you.
"I was lucky to have my family, especially my wife, she is a wonderful woman."
The midfielder said the prospect he might not pull through "was in his head every day" and told of the devastation of being told he would not play professionally again after a 17-year career in the sport.
He said: "It was heartbreaking. Football was what I wanted to do, all my life.
"I knew a lot about my disease but I didn't know it would be that hard.
"I just tried to think that everything would be okay."
Stiliyan has taken up a new role as an assistant coach at Aston Villa, but revealed he had recently told his wife that he was going to try to get back into the sport profesionally. He said: "She said, "No way."
However, he has been given permission to lace up his football boots once more for a Celtic Legends match on September 8 at Parkhead, which aims to raise money for Stylians's nominated charities.
He said: "I'm really excited about it. We've got a couple of big names lined up already. I'm going to play a part in the game.
"I have been training and am feeling it in my knees now."
Tickets for the game are on sale. They are £10 for adults and £5 for concessions.
They are available online, by calling 0871 226 1888 or from the Celtic ticket office.
PETROV ON HOOPER SALE – Page 55