Ben Stokes believes he let both himself and England down during the 4-0 Ashes defeat in Australia.
The all-rounder, who averaged only 23.60 with the bat and took four wickets, said Joe Root’s side have taken some "hard lessons" from the chastening defeat Down Under.
Stokes helped to salvage a draw with a half-century in both innings in the fourth Test at the Sydney Cricket Ground, but England suffered a brutal series hammering.
The vice-captain, who returned in Australia following a break to protect his mental health while also recovering from a finger injury, is determined to make amends in the upcoming series against West Indies.
"Looking back on Australia, we've had some honest reflections not only as a team but individuals as well," the 30-year-old said.
"I personally felt I let the team down with more than just performances, I would have liked to have been in better physical shape.
"When I look back on it, I felt I let myself down, but the thing that really grinds me the most and hurts me the most is that I let a lot of other people down and I never want to feel that way again.
"Everyone's taken some good hard lessons from Australia."
England travelled to the Caribbean without legendary bowlers James Anderson and Stuart Broad, while head coach Chris Silverwood lost his job after the drubbing in Australia.
Stokes is fully behind captain Joe Root and says there is no point discussing the absence of Anderson and Broad.
"It's not all on the captain. Joe is 100 per cent the man to lead this team forward, and I'll be right behind him every step of the way,” he added.
"There's obviously been a big change with Stuart and Jimmy [being dropped,] but, with all due respect to them, they're not here and what we can concentrate on are the guys who are, and the opportunity they now have.
"We have made a real effort to make sure that from the top, the most experienced guy, Joe, to the guys who haven’t even played yet, we are valued just as much as each other.
"When it comes to guys who are about to make their debut or haven't played much, there is that extra responsibility on the senior guys to help them through that.
"I don't see it as a negative whatsoever. The only thing for us now is [to be] positive, because there were a lot of negatives in Australia and it was a s*** place to be."
The first Test in the three-match series against West Indies start in Antigua on Tuesday.