He said: "I was speaking to a couple of people who are close to me and felt it was time I started thinking positive again and playing positively again.
"I feel I've been concentrating on the defensive side of my game too much which isn't really what I came here for. I'll hold my hand up and say I'm not the best defender in the world but I'll try my hardest for the team.
"It's just about trying to play my own game again and that's the way I enjoy playing and that's the way I benefit the team more so hopefully that's the way I'll try and approach things.
"I'm probably my worst critic. I really am but there comes a time when you say you've got to stop beating yourself up about it because at the end of the day it's your job and you've got to switch off when you go home.
"You've just got to start enjoying football again and that's the key really, enjoying it. When you are enjoying it things come naturally and that is what happened today and hopefully that is a corner turned."
McSheffrey added: "We have given them a hard game and they did a typical United job and won 1-0. If you keep clean sheets in this league, you win games. It's obvious.
"But if we play like that, we will win and draw more games than we will lose. We are confident going into the next game now at Blackburn even though we lost."