Marc, aged 46, an Owls player in their glory days in the 1990s, had an operation this week to try to help him after losing the use of his lower legs, having initially suffered from a back complaint.
His condition, which has baffled doctors, worsened.
Then things went from bad to worse one afternoon after he arrived home after driving one of his sons back from an activity.
Marc, from Kelham Island, said: “For about a month, I’ve been struggling with a bad back. It turned into not being able to walk for long.
"It gradually got worse until I fell getting out of my car because my leg gave way, which made the leg, from the knee, all the way to the foot, dead. No movement, no twitching, nothing – I can’t use it. I was taken to hospital. Two days later, my right leg had gone exactly the same.
“I’ve got two legs that don’t work. I’ve been told I could be in rehab for three to nine months which is leaving my wife and four kids at home to cope without me, which is pretty upsetting.”
Doctors at the Northern General Hospital this week operated on some of the discs around his spine. He said it has lessened the pain, but his legs will still not work below the knees. But he said they were not certain exactly what was wrong.
Marc said he had been optimistic since the problem started and would not let it get him down – he is determined to stay strong for his family.
But he is concerned that he is unable to do the trade he took up after leaving his football career – as a self-employed tiler.
Marc said his friends had been fantastic in the way they had supported him through errands and fundraising. He said he has also received support from his former club’s community team.
"There has been so much love from everyone,” he said. “I’m lucky to have such great friends.”
Marc was a Sheffield Wednesday apprentice for two years, and then on the books as a professional for another two years, between 1991 and 1995.
He was a member of the playing squad which reached both the FA Cup final and the League Cup final in 1993.
A right back, he was part of the first team squad for a cup clash, but did not get into the pitch. He played many times for the reserves at a time the players included big names like Chris Waddle and Des Walker, under manager Trevor Francis.
After leaving Wednesday he went on to play semi-professionally for Belper Town, Sheffield, and Hallam.
He said: “My priority is to get rid of the pain. My next step will be to walk again. I’m hoping over time my legs will slowly come back. It may hurt, but I’m determined to walk again.”