Wijnaldum, 30, joined the French club on a free transfer in June after saying he didn't "feel loved and appreciated" at Anfield.
However, the midfielder has made only six starts for PSG in all competitions this season and said it has been difficult to adjust to his lack of playing time.
"I can't say I'm completely happy, because the situation is not what I wanted," he told NOS. "But that's football and I'll have to learn to deal with that. I'm a fighter.
"I have to stay positive and work hard to turn it around. I have played a lot in recent years, was always fit and also did very well. This is something different and that takes getting used to.
"I was really looking forward to the new step and then this happens. It is very difficult."
Netherlands coach Louis van Gaal said he was "worried" about the midfielder's lack of minutes with his club, but Wijnaldum was called up to the national team for this month's World Cup qualifiers.
Wijnaldum missed the win over Latvia through suspension but captained the side for 90 minutes in the 6-0 win against Gilraltar on Monday.
Wijnaldum will return to club action when PSG host Angers on Friday.