Alastair Cook has admitted that he had "been to the well" too many times to carry on as England captain, as he spelled out his reasons for stepping down after a record 59 Tests in charge.

Speaking at Lord's for the first time since his resignation was confirmed, Cook admitted that he had been left drained by a tough winter campaign in the subcontinent, which culminated in five Test defeats in England's last six matches, including a maiden Test defeat against Bangladesh and a 4-0 series loss to India.

"It was an incredibly tough decision to make," Cook told Sky Sports. "I've loved every minute as England captain, but it's a job you have to commit 100% to, and there've been certain times throughout my four or five years in the job when I've been to the well and dug pretty deep.

"And coming back from India, the way I felt then, I didn't think I had it in me to do it again, because this isn't a job where you can operate at 95%.

"When I looked in that mirror, I felt it was time. It was sad in one way, because I've loved the honour and prestige of all of it. I've been leading some great men and had some great moments as England captain, but I do think it's the right time for me and for the team."

Cook's career included some notable high points, not least his maiden series as full-time captain in 2012-13, when he led England to a stunning 2-1 series win in India, and last year's away win in South Africa. But the low moments were particularly bruising, not least the Ashes whitewash in 2013-14, which presaged the most testing period of his tenure - the sacking of Kevin Pietersen ahead of the 2014 home season.

Cook was present at the ECB meeting that signalled the end of Pietersen's England career, and he bore the brunt of much of the fall-out for the rest of that summer. "I think we all have regrets over how it was handled," he admitted. "I was part of that decision, I wasn't the be-all-and-end-all of it, but what followed was part of the responsibility I had as England captain.

"The fallout wasn't great for English cricket, we were in the headlines for the wrong reasons, especially when our job as players is to promote the game as best we can, so it was not the best six months. But things have moved on, and since Andrew Strauss has come in [as England director], he's done a great job and made it clear that the side has moved on."

While insisting that his tenure wasn't "all doom and gloom", Cook did single out England's supporters for particular gratitude, not least those who gave him an ovation at the Ageas Bowl during the 2014 home series against India, when Cook was enduring some of the worst batting form of his career.

"I'll never forget Southampton, the warmth I had there in 2014," he said. "That kept me going, and of course my family and friends who mean the world to me and stuck with me through the tough times."

Asked if he would have any advice for his younger self, or for that matter the player who is appointed to succeed him, Cook - a famously stubborn individual - was revealingly candid.

"The advice I needed was to make sure you don't always do it your way," he said. "There are a lot of great people out there who watch a lot of cricket who know probably more than you do. So use that advice and be open to it. Ultimately you have to make the decision out there yourself, but use as much as you can. A lot of people want you to do well, because people love seeing England win games of cricket.

"It is a challenging job, you don't know what will be thrown at you at certain times. But I have loved it, and that is what has made the decision quite hard, because I knew what I was giving away. I look forward to the next part of my career, supporting the next guy as best I can, and hopefully scoring some runs as well and being part of England's success."