"We lost a big opportunity to stay in the fight," Ancelotti told BBC Sport. "We're still in the fight but with less possibility and more difficulties.
"We didn't start the game as well as this kind of game demands. It was an important game and would have been an important result."
The Toffees have collected just 19 points from 17 home matches, with eight of those games ending in defeat.
"It's unbelievable. It's difficult to explain why, but it's true," Ancelotti said of Everton's home record.
"The away run we have is also unbelievable. The home run has affected us in the table. I hope it doesn't affect us in the end."