Chaz Powell, who is originally from Newport, set off on his 2,575-kilometre journey in August focused on raising money and awareness for wildlife conservation charity the David Shepherd Wildlife Foundation.
But word got around about his antics and he was advised to quit before he was either kidnapped for a ransom or even worse.
Today Chaz spoke of his amazing experiences and how bitterly disappointed he was not to be able to complete his journey.
He revealed that security advisers told him that the danger levels were simply too high in Mozambique.
After just over three months of walking solo along 2,000km of the wildest river in Africa, the 37-year-old expedition leader was forced to end his journey when he was labelled a huge target for kidnap or even murder.
He said: "Unfortunately my journey has come to an abrupt end.
"It was a heartbreaking decision but, with rebel forces killing people and taking hostages in the areas I would have been walking in Mozambique, it was too dangerous to continue.
"It's a bitter pill to swallow, especially after walking so far and completing three quarters of my journey.
"It was the craziest journey of my life. I'll continue with the walk as soon as the issues in Mozambique have died down but for now I'm focused on planning talks about this wild journey and sharing my story."
Armed gangsters from the country have caused chaos along the South African border, using AK-47 weapons to rob owners of 4X4s and sports utility vehicles.
Australian visitor Elly Rose Warren, 20, was also murdered in the Mozambique resort of Tofo Beach last month.
Chaz said: "It's a bitter pill to swallow, but I am determined to continue with the walk as soon as the issues in Mozambique have died down."
He said he had some amazing memories about his adventure and met some incredible people along the way.
Despite being ahead of schedule when forced to cut his journey short, the constant threat of wild animals, dehydration and heat stroke ensured Chaz's adventure was never a quiet one.
After one month of walking Chaz was faced with the challenge of crossing the Barotese Floodplains, running from Mongu in Zambia all the way to Livingstone.
Chaz said: "Crossing the floodplains was like negotiating a maze of swamps, I would get so far along a path, to then be wading through swamps up to my waist at times, and then I would cross to the other side of the river and hit the same problem.
"It was tough going and took me about three days longer than I expected to get through the worst section."
With 1,300km trekked and on the road for two months, Chaz reached his halfway point, Victoria Falls in southern Zambia.
He said: "One of my highlights of the journey was visiting the many schools that run along the Zambezi.
"Most of the children, and even some of the adults I met on a daily basis had never seen a white person before and their curiosity fascinated me. It was very surreal."
Chaz's next challenge was crossing though the Zambezi gorges. He said: "The gorges were one of the most beautiful, yet deadly places I have ever been.
"They nearly cost me my life when I became lost after trying to head to higher ground and take a short cut.
"I ended up lost, without water, seriously dehydrated and fading fast. I had to alert my SOS on my InReach device, but after a failed rescue attempt I was forced to drink my own urine and clamber down near vertical cliffs to reach the river below. It was the scariest and most eye-opening experience of my life."
After recovering from the gorges Chaz made his way around the world's largest man-made lake, Lake Kariba and pushed on to the Lower Zambezi National Park and ever closer to the Mozambique border, the final country to pass through before reaching the Zambezi river mouth on the east coast.
But due to conflicts in Mozambique, he was turned away. He said he was absolutely gutted, but will finish his journey as soon as possible.
For more information or to follow Chaz's future adventures, visit facebook.com/TheWildestJourney or to donate, visit justgiving.com/WalkingTheZambezi