The TV presenter was hospitalised after being struck down by a mystery lung infection on a flight from Los Angeles to the UK earlier this month.
Just 90 minutes after walking into Lewisham hospital and “complaining of shortness of breath” he was placed into a medically-induced coma to allow his body to fight the infection.
In an interview with Radio 5 Live, the 42-year-old described coming round from seven days of sedation as “the worst day of [his] life”.
“I remember going under,” he explained. “The coming round is the strangest period of my life because it’s so long. They brought me out after seven days and I had the worst day of my life.
“It’s hours and hours later before you rejoin the world. I was frightened and I was really kicking off to the point they had to restrain me. In the end they put me back under and brought me out slower after two days.”
The broadcaster went on to explain that he struggled to separate fact from fiction because of the hallucinations he experienced whilst he was in a coma.
“You start to piece together a fiction and there were things I thought 100 per cent are true,” he said. “There were things I could remember that were accurate and things that were nonsense. I’ve had to unpick truth from fiction.”
The former ‘Blue Peter’ presenter revealed he still cannot eat or sleep properly and is still coming to terms with his physical appearance.
“The physical change is the hardest thing,” he said. “To look at myself in the mirror now I’m incredibly gaunt and thin.”
After leaving hospital last week Richard paid tribute to his wife Rebecca in a touching tweet.
“Last full day in hospital. Every facet of my life would be worse without Rebecca in it. How will I ever thank her?” he tweeted.
The message continues: “I was in a coma for nine or ten nights (I just learned). That’s a lot of staring at your husband and his pipes. And a lot of worry.”
He also took the opportunity to praise the NHS and Lewisham Hospital, where he was treated.
“Low on energy but I love and admire all the team LEWISHAM HOSPITAL. VivaTheNHS,” he tweeted.