SAS: Who Dares Wins sees the toughest contestants go up against some seriously tough challenges to see if they have what it takes to win the special force.
Even just getting on the Channel 4 show is a huge achievement, never mind completing the tasks.
Nathaniel was the latest recruit to withdraw from the process, this time on medical grounds.
It came after the contestants had to do a team task where they had to work together to move heavy ammunition from one spot to another before setting up the weapons to fire them.
When the group headed out the following day, Nathaniel pulled chief instructor, Ant Middleton, to one side to discuss his state of mind.
He admitted: “Fitness wise, I’m one of the fittest here but mentally I’m not.
“It’s my f**king head, it always holds me back.”
It was revealed earlier on the show Nathaniel had attempted to take his own life at one point.
He wanted to try and succeed on SAS: Who Dares Wins to show people mental health doesn’t always hold them back.
However, he was advised to leave the process on medical grounds by the on-site medic.
Nathaniel has since spoken exclusively to Express.co.uk to discuss his time on the show.
He explained he didn’t initially go on the show to talk about his mental health battles, but they came out.
The recruit said: “I tried to hide it, my mental health.”
“When I say prove a point, I was going to go on an try to get to the end and then say I was mentally ill – that was the point I wanted to prove.
“Just because I have mental health problems it doesn’t mean I can’t do as well as everybody else, but obviously I went in the show ill, like really ill, and I kind of couldn’t really hide my mental health [and] it came out on the show.
“It was a very tough thing to do but on top of that, I had my own demons at the time.”
Later on in the show, Nathaniel gave the team a letter to read out to the rest of the recruits.
It read: “Hello guys, it’s Nathaniel. I wanted to write to you to explain the reason for my leaving. I’ve been medically discharged because of my health.”
Going on to discuss a difficult time at university, the contestant added: “I fell so far down I didn’t think I could get back up. But when you fall on your back you can’t fall any further.
“I’m physically able to carry on, but mentally, I’ve reached my limit. This is a new chapter for me and you guys have been like family for me. This is only the start of my journey to recovery – there’s no switch to turn mental health on and off.
“I’m sorry if I’ve let you down but I have to put my health first. It’s been an amazing journey and I’ve grown as a human being and a man.”
SAS: Who Dares Wins continues Sunday on Channel 4 at 9pm.
For confidential support, call the Samaritans in the UK on 116 123 or visit a local Samaritans branch.