"It's hard, I've only started a few games since I've come back," the England Under 21 international told the Gazette.
"It's been frustrating for me but I've got to get my head down and get on with it.
"I want to stay here and I'd love to make it here but it just isn't happening at the moment.
"Maybe I can make an impact in the final few games, but I'm hoping to sit down at the end of the season and take it from there.
"The gaffer is great with me and understands my concerns and how I feel," said Johnson.
"He wants me to play games but also wants me here and needs me.
"When I come on I want to impress people so I can play more, so I can start to show people what I can do, but obviously that hasn't been happening.
"I had a run of games at Watford and it always helps a player when you are going to play week-in week-out.
"It gives you confidence just playing every week knowing if I had a bad game I wouldn't be dropped straight away."