The Glasgow-born BBC presenter admitted yesterday he had been “grossly overdoing things” in the run-up to being rushed to hospital hours after exercising on a rowing machine.
He also blamed self-inflicted problems in his personal life – including an extra-marital affair with a fellow journalist.
However Marr, who is due to make a public appearance at the Edinburgh International Book Festival in August, said he now owed his life to his wife, Jackie Ashley.
Marr, who started his journalistic career at The Scotsman, sister paper of Scotland on Sunday, was taken ill in January.
The 53-year-old, giving his first in-depth interview, refused to let his wife phone a doctor after suffering headaches – triggered by tearing his carotid artery, which supplies the head and neck with oxygenated blood.
Marr said: “I didn’t let her. I was still convinced it was a bad headache. The colours in my eyes had gone, although I was still exhausted, which I put down to the hard bout on the rowing machine. I felt ill, but not very ill, so I took two paracetamol and went to bed.
“It would have made a big difference, but I wouldn’t listen.” Marr fell out of bed in the night and could not get up in the morning as his left arm and leg “weren’t working”.
At the time Marr had weekly TV and radio shows, and had also been making a history of the world series.
He recalled forgetting his lines while filming in Macedonia as a possible warning sign that all was not right.
Marr said: “I was working too hard. No-one made me do it, that’s just the way I am.
“I’m a gulper, a gobbler-down of life. I wolf experiences down and, that year, I pushed my body and my mind too hard and far.
“No-one seems to know for certain what causes a stroke, but having had time to think, I can now see that I had been grossly overdoing things.
“It had also been easily the most stressful time of my personal life – and entirely my own fault.”
Recalling the aftermath of his collapse, Marr said he was given clot-busting drugs which he was warned could have “catastrophic side-effects”.
“There is no doubt they saved my life, but there was a second bleed into my brain. My condition seemed to be very much touch-and-go.
“I wouldn’t know this until later, but Jackie was twice given the clear impression that I was a goner. If I was very lucky, I would be a vegetable, unable to move, see, hear or speak.”
The stroke hit the left hand side of Marr’s brain and he is now undergoing physiotherapy and intensive rehab in the hope of returning to work
Marr added: “Jackie saved my life. Without her, I wouldn’t be here. She was very brave and very sensitive in not telling me everything until I was stronger. And then she really carried me…
”She has been completely calming and reassuring, as well as a great practical carer, and the whole experience has brought us more closely together.”