Stephens concedes he needed a summer "reset" to find his motivation again.
He told the club's website, “I think last year, mentally, I was struggling a bit with football.
“I was having a bit of a tough time on the pitch. I was letting it get to me a little bit and my performances probably showed that.
“I didn't let it affect my life outside of football – I was fine, I was happy, but obviously football is my job and it's my life.
“I think it happens to every sports player – you have difficult times. As footballers, there are constant ups and downs.
“It's sometimes difficult to deal with that, because one minute your emotions are sky high and the next minute you're rock bottom."
He points to his family and friends back in Torpoint, Cornwall, where Stephens grew up and still loves to visit, which offers a release from the pressures of the day job.
Over the summer, he says, he had to “reset".
“It was nice to have that break," he explains. “I gave myself the best opportunity of coming back ready for pre-season.
“I just wanted to try to improve as many aspects of my game as possible, but especially the mental side – trying to be mentally strong and really mentally driven to reach my goals.
“I'm lucky enough I've got good family around me and good friends who have believed in me, so I just have to take their advice and believe in myself."