QPR's relegation was confirmed on Sunday following a goalless draw with Reading, who also dropped down to the Championship, and Samba admits the players are devastated.
The former Blackburn centre-back only arrived at Loftus Road halfway through the season from Anzhi Makhachkala and had been confident he could help keep the club up, but he admits he was not at his fittest when he made the move.
He told Sky Sports News: "There is a big feeling of failure. Most of us came to help the team, believing we could have an impact.
"There are good people at the club. Tony Fernandes is a fantastic guy and was working to transform it into a big club.
"It is a shame but we need to stay strong for the future and try to give what the club deserves."
Asked for the possible reasons behind QPR's relegation, Samba added: "From my personal point of view, I don't think I was well prepared to come back to the Premier League. It is the hardest league and you need to be fully fit and really ready to compete.
"We had many chances to get out of it and didn't take them, but that is football."
It has been suggested that there have been divisions in the dressing room which have contributed to QPR's miserable campaign, but Samba insists that would be too simplistic an explanation.
He said: "I don't know if we can say it is divided. What I can say is that at every club there are affinities. You go into work and you like to sit with specific people, that is what happens, but if everybody respects each other they can work with each other."
Samba did not want to comment on criticism of the club from midfielder Joey Barton, who is currently on loan at Marseille, and was also coy about his own future.
He says the one thing he can guarantee is that he will be better prepared for next season but he is not sure whether QPR will keep him.
He said: "I don't know. I am not the only one who makes these decisions. I have failed to help the team and I only know that I will be much stronger next season."