He said it “feels like a bereavement” after the former EastEnders star left the couple’s home in mid-July.
The actor was diagnosed with Alzheimer’s in 2014 and her condition has worsened during lockdown.
Speaking to The Sun, Scott said: “I feel I’m on an emotional rollercoaster. I walk around, trying to keep busy, then burst in to tears. It feels like a bereavement.
“It’s always been my biggest fear, that one day I would have to take her somewhere and she’d be thinking, ‘Why would he do this to me?’
“That fear has become a reality. It’s something I never wanted.”
Scott said he has decorated Barbara’s room in her London care home to make it as welcoming as possible.
He has put up family pictures as well as a photograph of the actress receiving her damehood from the Queen and a snap of her with Paul O’Grady and Cilla Black at the Royal Variety Performance.
Speaking of the day he left his wife at the home, Scott said: “I’ll never forget the feeling of emptiness. I felt sick in the pit of my stomach that I’d left her. I still feel like that.
“By the time I got home and went to bed, I just felt desperately sad. It’s been 27 years since we met and we spent so much of that time in each other’s company. It feels like another chapter has gone.”
Dame Barbara was diagnosed with Alzheimer’s six years ago and went public with her diagnosis in 2018.
Back in June, Scott revealed doctors had told him to be prepared to move Barbara into a care home, admitting he’d had some “fairly dark moments” since then.
Barbara’s former EastEnders co-star Ross Kemp – who filmed a documentary about Alzheimer’s, in which Scott featured – said that seeing “the deterioration” in her condition had been “shocking and, to those of us close to her, deeply upsetting”.
Both Dame Barbara and her husband have campaigned to raise awareness of the illness, which is most common in people over the age of 65.
This article originally appeared on HuffPost UK and has been updated.