Paul Lambert's young team held firm for the majority of the game, with the Reds unable to either pass their way around or penetrate the resilient Villans' backline, which again prevailed in a 3-5-2 formation.
Brendan Rodgers' side have now picked up just 12 points from a possible 27 at home this season, carrying on their poor form from last season in which they dropped 30 points in their 19 games at Anfield.
Johnson admits that their failure to accumulate victories at Anfield could be the difference between Champions League and Europa League football next season, and says they need to put the defeat behind them quickly.
"Any game you lose is disappointing," Johnson told the Liverpool Echo.
|RODGERS SHOCKED BY LOSS
|16/1||Liverpool are 16/1 with bet365 to beat Fulham 2-1 at Anfield
"It was a great opportunity to pick up three more points and we missed out. We have to put this behind us. It's gone now and there's nothing we can do about it.
"We have a lot of games coming up and we have to look to put things right next weekend."
The marauding right-back, whose shot was turned in by Steven Gerrard for a consolation goal, also felt that Liverpool were unlucky to fall behind as they had dominated possession.
He continued: "Early on we had so much of the ball and dominated the game. They went in front completely against the run of play.
"When we were 1-0 down, we still had a big chance as there was plenty of time left in the game. But the second goal before half-time left us with a lot to do.
"You can say we needed to pass the ball that bit quicker, but sometimes it's difficult to play too quick because you have so much room.
"When you're in loads of room then you are supposed to move into that space. When the opposition are so compact around the edge of the box then your little passes have to be perfect.
"When you have a day like we did when your passing isn't perfect, that makes it very difficult to break them down."
On Saturday, Liverpool welcome a Fulham side with the second-worst away defence in the league but also know that they themselves will need to be alert at the back as no team outside the top five have scored more goals away from home than the Cottagers this season, with 13.