The Yorkshire batter stepped down in April after five years in the job with a record number of matches and wins as skipper.
But the 31-year-old said the role had started to become "something slightly unhealthy".
"The captaincy was starting to take a toll on me," Root told the Mail on Sunday.
"The limited time I did get to spend with family, which should be enjoyed and treasured, I wasn't able to do that. I wasn't really there. I came to realise that that had been the case for a little while.
"There were times when I was thinking about something I couldn't control or something that hadn't happened previously. You go in on yourself.
"We would still do what we would normally do as a family but I would not be listening. I just felt like a bit of a zombie almost.
"I could start seeing it have an impact on me as a person. You want to bring your personality to the role, not bring the role to your personality. It was reversing into something slightly unhealthy."
Root was replaced as Test captain by Ben Stokes and the Yorkshireman played a key role in a successful summer for England's red-ball side, scoring three hundreds and averaging 68.33.