The 49-year-old Malaysian businessman took over at Loftus Road in 2011 and put more than £50 million of his own money into the club.
"I think I allowed myself to be exploited but that's my choice," he said. "I don't think I will be exploited any more," he told the BBC on Saturday.
Rangers signed high-profile players including Djibril Cisse, Bobby Zamora, Christopher Samba and Loic Remy but they have won only four matches in the Premier League this season.
"Agents are trying to get the best contracts and there are no two ways about it, I had to pay premiums," Fernandes said.
"I've seen all of the parts that make football quite - maybe immoral is a strong word - but they would sell their grandmother to do something. It's all part of the football ecosystem."
Fernandes said last week that he felt disappointed by the attitude of some of the club's players when they lost matches and warned that it could take two or three seasons to return to the top flight.
QPR allowed experienced midfielder Joey Barton to join French club Marseille on loan this season, a decision Fernandes regrets.
"We missed Joey," he said. "We needed a workhorse midfielder and we tried to get (Tottenham Hotspur's) Scott Parker. We missed a real leader."
"This has been a tragic season in many ways. It is a Shakespearean play in the making."