The 30-year-old Team Sky leader completed his victory in the 102nd Tour in Paris yesterday.
Froome, who also won the 2013 title, had to dig deep on the penultimate stage to Alpe-d’Huez to limit his losses to Nairo Quintana, who finished one minute 12 seconds behind to end up runner-up to Froome for a second time.
“There are all kinds of things going through your mind,” Froome said.
“It’s forever this argument you’re having with yourself, in your head, how much deeper you can go, how much suffering you can take.”
Froome felt the yellow jersey slipping through his grasp on the climb of the Col de la Croix de Fer as Quintana and his Movistar team-mate Alejandro Valverde, who placed third overall, tried to turn the screw.
“Once Quintana and Valverde had got that little gap, that was quite a pivotal moment of the race,” added Froome, who battled a chest infection in the third week of the race.
“If Richie [Porte] hadn’t got me close enough for me to be able to jump across like that, if I’d tried to jump across on my own and they had accelerated and I was in no-man’s land, that could’ve been the Tour, that could’ve been the leader’s jersey gone.
“There were definitely some moments where it was touch and go.”
Quintana made gains on the final two stages in the Alps, to La Toussuire and Alpe-d’Huez.
Had there been another, the race might have had a different winner.
“I feel as if I’ve reached this point where I can ride at a good tempo, but I’m struggling to go any deeper than that,” added Froome, who also became only the second British winner of the King of the Mountains title in the competition’s 40-year history after Scotland’s Robert Millar in 1984.
It was on the flat, rather than in the mountains, where Quintana felt he lost the Tour, losing 1min 28secs on stage two to Zeeland.
Froome anticipates further duels with the Colombian climber as he bids to ride on for at least five more years.
But the Kenya-born Briton believes future courses should be more in his favour if they include a time-trial.
“If any Tour route were to be in his favour it would’ve been this one,” added Froome, the Olympic time-trial bronze medallist.
“I love this race, I love this sport. If physically possible I’d like to keep doing it as long as possible.
“I genuinely want to try to see out my career and really push myself to the limits, to do what I feel I’m capable of doing.”
Froome enjoyed a beer – his first since Christmas – with his team-mates on Saturday night and was indebted to them for their support over three turbulent weeks.
Team Sky riders were abused by roadside spectators and Froome was called a ‘doper’, had urine thrown at him and was spat on as unfounded allegations were made about his performances.
The climate of suspicion was a legacy of the drug-assisted era, but Froome and Team Sky insist they do not dope.
Froome used his victory speech to make a veiled reference to his critics, vowing to honour the yellow jersey.
He said: “The maillot jaune is special, very special. I understand its history, good and bad, and I will always respect it, never dishonour it and I’ll always be proud to have won it.”
Asked what honouring the yellow jersey meant to him, Froome said: “It’s pretty straightforward: in this day and age I feel someone needs to speak up for the cyclists of 2015 and, of course, I’m happy to do that.
“I’m in this position now. Someone’s got to take a stand, it’s time.”