Scott Wilson, 46, from Biggar in South Lanarkshire, lost his gardening business and career as a reserve firefighter after developing Parkinson's. He sold his home to the council and separated from his partner who left home with his two children.
Mr Wilson stayed in his disability-adapted two-bedroom house under a mortgage-to-let scheme but has now been told he has to move out or have his housing benefit cut, Holyrood's Welfare Reform Committee heard.
The committee is taking evidence on the UK Government's under-occupancy charge, also known as the bedroom tax.
The policy cuts housing benefit by up to a quarter for those deemed to have additional bedrooms in their home, but the committee heard that people have had to borrow to meet extra costs such as moving vans and vehicle fuel.
People have also had to abandon their possessions and self-purchased fixtures and fittings to move into smaller properties if they are available, the committee heard.
Mr Wilson may have to move up to 20 miles away because of a shortage of one-bedroom homes in Biggar, separating him from his son who has a heart condition and daughter who is expecting his first grandchild, he told the committee.
"I recently separated from my partner of nearly 20 years, partly because of the stress that Parkinson's has put on my family life and relationships. I have lived in my home for 25 years. We had to sell it back to the council because of financial hardship," he said.
"I was shocked when a council employee phoned and told me that my housing benefit would be cut to the equivalent of a one-bedroom home and that I would have to find the additional money from my benefits to pay for two bedrooms.
"I asked the person on the phone about how I could have my daughter and expected grandchild or my disabled son to come and stay with me if I moved to a one-bedroom flat, or shared my home.
"I asked, 'where were they were expected to sleep?' And was asked, 'Have you never heard of inflatable beds'?
"Mortgage-to-rent was the only way for me to stay in my family home which I had decorated and made my home over 25 years, and now someone wants to take it away from me, rip out the kitchen that I put in and the bathroom and give it to someone else just for the sake of making it easier for the Government to claw back some money.
"The council gave me a wet room and adapted my house because I'm now living alone with Parkinson's and now I'm being told to move out.
"I'm going to be a grandfather in a few months but they're expecting me to destroy my family life and move into a one-bedroom house. I'll fight it all the way. I'll not go.
"In the area that I live, you're lucky if there's a dozen one-bedroom houses. But for me to move from a two-bedroom into a one-bedroom, trying to fit all my furniture in, is just unfeasible.
"I only live three miles from my son now so it's easy for me to see him. It's hard enough to pay for heating, gas, electric and council tax, but if I moved 20 miles away I would have to fork out a fortune in diesel to see him. It would devastate us.
"Because of his condition we need to be on 24-hour call for a slot coming up for the serious operations he needs. If I'm 20 miles away my ex-partner would be at her wit's end."
The committee also heard a submission by widow Linda Kennedy, 58, from Glasgow, who has had to borrow from her pregnant daughter and son to cover the shortfall in her housing benefit.
Daughter Lyndsay Ferry, 29, told the committee: "My extra money would have gone to my baby, but I'm now in a position where I have to help my mum."
Anne Bradley, 54, from Glasgow, told how Queen's Cross Housing Association staff suggested she take in a lodger to avoid her benefit being cut.
"I would never take a stranger into my home," she said. "It has cost my family money financially to help me to move. Without them I wouldn't have been able to move and now I owe them money, otherwise I would have ended up homeless."