Redknapp accepts QPR are now down.
"It is disappointing but I've had other disappointments and I'll have more in the future I am sure," Redknapp, who was last relegated eight years ago with Southampton, said.
"I get as disappointed as anyone when it doesn't go well but you can only do what you can do.
"I can't look back and say I have not worked hard and tried hard because I have. I have given everything and at the end of the day it just hasn't been good enough.
"We've got to keep going, we've got to keep playing. We need to make sure we prepare right this week to play Reading next week.
"You owe that to the supporters. They are going to travel to Reading and want to see a performance next week. That is what we have got to try and do."