Prince Harry attends an Invictus Sydney launch. Photo / Getty
Prince Harry has described in detail the panic attacks he suffered because of the death of his late mother, saying his body felt like a "washing machine".
According to the Daily Mail, in an interview to publicise the forthcoming Invictus Games, a Paralympic-style event he devised for injured service personnel, the Queen's grandson said he would become ill "every single time" he found himself in a room full of people.
Speaking to Forces TV, he said: "When you can get your own head and self back on the right path, the amount of people you can help is unbelievable, because you can tell the signs in people. You can see it in their eyes. You can see it in them, their reactions.
"In my case, suit and tie, every single time I was in any room with loads of people, which is quite often, I was just pouring with sweat, like heart beating - boom, boom, boom, boom - and literally just like a washing machine.
"I was like, 'Oh my God, get me out of here now. Oh, hang on, I can't get out of here, I have got to just hide it'".
Earlier this year the fifth in line to the throne admitted for the first time that he had sought professional help for his mental health issues at the age of 28 after what he described as "two years of total chaos".
It was during this period he first began to suffer panic attacks during royal engagements and was feeling "on the verge of punching someone".
Since conquering his own demons, the Prince has turned his focus to publicly helping others battling mental health illness, along with his brother and sister-in-law.
Speaking to his friend, Dave Henson, a double amputee and former Invictus competitor who went on to win bronze at the Rio Paralympics, the prince said: "You go through all that stuff and then you met other lads who are on a similar journey or the similarities are there.
"You help yourself so you can help others. That is hugely powerful.
"So many people are, you know, like slightly mental. Awesome! We are, we are all mental and we have all got to deal with our stuff.
"Rather than running around at 50 per cent capacity, imagine if we could run around at 100 per cent capacity. Imagine what we could achieve."
Harry, 32, also reveals in the interview how fighting in Afghanistan was the "trigger" that finally forced him to deal with his mother's death, which happened 20 years ago this August.
The prince, who was 12 at the time, went on to graduate from Sandhurst and undertook two frontline tours of Afghanistan, finally leaving the forces after ten years.
He said: "Once I plucked my head out of the sand post-Afghan - yes, it had a huge life-changing moment for me as well.
"I was like, right, 'You are Prince Harry. You can do this. As long as you're not a complete t*t then you are going to be able to get that support because you've got the credibility of ten years' service and therefore you can really make a difference".
"Actually going through Invictus and speaking to all the guys about their issues has really healed me and helped me.
"I have got plenty of issues. None of them really relate to Afghanistan but Afghanistan was the thing that triggered everything else and the process.
"If you lose your mum at the age of 12 you have got to deal with it.
"The idea that 20 years later I still hadn't really... that 15, 17 years later I still hadn't dealt with it. Afghan was the moment where I was like, 'Right, deal with it.'
"Sharing the stories and being amongst people who you know that when they tell you the issues they are having it is like, 'Yeah, been there done that. Yep yep yep yep yep.'
"And you go through all these lists and you are like wow, so actually we have got a lot more in common than would meet the eye.
"Then people suddenly jump to conclusions and say, 'Oh, it must be Afghanistan.' No.
"So many people who suffer from depression, anxiety, alcoholism, it can be from when you were younger and Afghanistan is the trigger to bring it all to light and to deal with that stuff."
Asked whether he had been inspired to set up the Invictus Games, which will be held in Toronto this year, to in part deal with his own issues, he replied: "Yeah, 100 per cent. For me, Invictus has been sort of like a cure for myself."
Harry said setting up Invictus has been a "wonderful journey" and that watching the injured competitors competing is "an inspiration that this country needs".
"Everybody needs to get up off their arse and just say, 'You know what, I'm not beaten, I'm unconquerable. Let's do this,'" he added.