Despite joining for a reported £45 million in August, the Iceland international is yet to register either a goal or assist from seven Premier League appearances.
That comes as Everton, who were tipped to challenge for a top-four finish at the start of the season, sit 16th with eight points from as many games after Wayne Rooney's late penalty salvaged a 1-1 draw against Brighton and Hove Albion on Sunday.
Sigurdsson told reporters: "It is not going as I hoped. No, of course not. For the team as well. Personally and collectively we are just off our best. That is reflecting in individual performances. But it's small margins. I don't think we're a mile off getting results. A couple of scruffy wins would bring some confidence to the team and that's sometimes all you need. We just have to work our way through this. We are not scoring enough goals and we are conceding too many, I don't think we are too far away but things just aren't clicking. We're all more than determined to turn it around. We have some big players and hopefully we can start getting better results."