The Coronation Street actress wrote in her autobiography From the Heart that despite an initial connection, she became irritated by Ryder's teetotal attitude.
Speaking about first meeting the actor, she said: "When I spotted him I told Myleene Klass, 'He's quite cute - except he looks about 12!' We chatted and he was flirting with me. I kinda liked him too. He had a very honest face and I could sense something between us. (sic)
"A few months earlier I'd been a single mum who spent her evenings ironing. Now I was being texted by the hottest soap star in the country."
Marsh explained how Ryder chose not to drink alchohol and preferred to stay in rather than attend celebrity parties.
"He said he'd got drunk once and it had made him do stupid things and feel sick so he'd decided never to do it again.
"It became clear that not only did Jack not like drinking, but he didn't seem to like other people drinking either. I'd never been a massive boozer but I did enjoy a few glasses of wine or Bacardi and Coke. After we got together, though, I felt I should cut all that out.
"It wasn't long before I figured out that he hated things like premieres and awards ceremonies. So instead Jack and I stayed in most evenings and watched films. There were times when I'd think, 'Here I am, in London in my mid-20s and I could go to any club I wanted, but I'm sitting here watching Star Wars again'.
"Jack never seemed keen on going out, so I never pushed it. Instead we'd just cook our tea then cuddle up on the sofa to watch telly.
"At that time I thought it was brilliant that he was so different to guys I'd met before. Most blokes are only interested in beer, sex and football (not always in that order!) but Jack wasn't like that."
She revealed that she did not enjoy their wedding in 2002 because Ryder wanted to leave the reception early.
"We hardly had any family photos because Jack said he'd had enough of having his picture taken after a short while. In the pictures, the wedding seems perfect. I hate to admit it - but I don't think I really enjoyed it.
"I really fancied a drink to celebrate but I didn't think Jack would be happy - so I stuck to Coca-Cola all day. He wanted to go home at 11.30pm - I was disappointed but I didn't want Jack to be in a bad mood on our wedding night."
The actress added that the pair struggled with their finances, due to Ryder leaving EastEnders and her group Hear'Say breaking up before joining Coronation Street.
On their eventual break-up, she explained: "I took a deep breath. 'I'm sick of this,' I said. 'I've just had enough of it'. There was silence for a beat. 'I agree,' Jack said. 'We can't go on like this'. Finally we were both admitting our true feelings and as I hung up I knew that was the end of my marriage.
"When we split up there seemed to be a general view that it was all my fault. I hope that by telling my side of the story people will understand things aren't always the way they seem to be. We just hadn't been right for each other from the start."
Kym Marsh is now married to Hollyoaks actor Jamie Lomas, and gave birth to a baby girl in March.
The actress said that she had no plans to "slag off" her ex-husband Ryder in her autobiography.
She recently dismissed a "nonsense" rumour that she had an affair with Ryan Giggs.