The manager lamented the late free kick that cancelled out Loic Remy's outstanding opener to leave the Hoops with just a point against their fellow relegation strugglers
Shaun Maloney struck deep into stoppage time to convert a free kick from the edge of the box that cancelled out the stunning opening goal scored by Loic Remy minutes earlier.
When asked if it was the toughest result in his time at Loftus Road, Redknapp told reporters: "In my football career, never mind the season.
"What have they [Wigan] done? They've kept the ball, passed it in front of us, but how many saves has our keeper had to make? Hardly any. My players are very low, as am I.
"If we had come off with three points with 10 men it would have given us a massive boost, a massive lift, and you'd have thought we could still win four games. But now it is going to be very hard [to stay up]."
QPR had already played 70 minutes with 10 men after Bobby Zamora's red card for a high challenge on Jordi Gomez, catching him in the face with his foot.
"It was a rash challenge [from Zamora," conceded the manager, who will be without the striker for the next three matches while he serves his suspension.