The Reds slipped to their sixth consecutive Championship defeat against Luton Town on Tuesday and are without a win in 13 league matches heading into Saturday’s clash with play-off chasing QPR at Oakwell.
They remain eight points from safety.
"It’s hard to explain because we are losing but we are actually playing good,” said Quina, who joined Barnsley on loan from Watford on deadline day, having seen his previous loan spell at Fulham cut short due to a lack of playing time.
“It’s not like we are being beaten by big margins.
"Everyone’s trying their best to get us to win that one game to get that momentum going. We just need to win one game to get everyone’s confidence high again so we can start going.
“I definitely believe, I have to. We’re improving game by game, we just need to score the first goal instead of chasing the game.”
Portugese youth international Quina revealed his main motivation for joining the Reds was game time.
The 22-year-old completed his first 90 minutes of the season against Luton.
"As soon as we get that win it will turn things around,” he added.
"The gap between us and the other teams isn’t that big, it’s doable.
"A lot of players still believe we are not going down and that’s important – you need to have that belief.”
Barnsley’s next opponents are currently fourth in the table and unbeaten in seven games.
Reds boss Poya Asbaghi also confirmed striker Cauley Woodrow could be out until April.