They are both "speechless" after wellwishers donated more than £ 13,000 for an air ambulance to fly them home.
Jon Paul McAllister, 38, and his partner Craig Park went on holiday to South Africa, Madagascar and the Seychelles to celebrate the end of McAllister's chemotherapy treatment and their January engagement.
Mr Park said he had gone to hospital on the long-awaited trip.
In Madagascar, Mr McAllister's health deteriorated rapidly and has been reunited.
Friends started a fundraising campaign on Friday to pay for the overseas treatment and an air ambulance flight back to Scotland, which they say will not pay out for.
The money raised is now more than a third of the way towards the £ 35,000 target.
So, here's a little insight into the year and my better have had experience. This is something we have …
Posted by Craig Park on Friday, November 2, 2018
Mr Park told the Press Association: "We are speechless. People's kindness and generosity is amazing. We were not expecting this at all.
Jon Paul has spent his working life giving to other people. He looks after all his clients, friends and family and is extremely selfless.
"He never asks for anything but this is one of those times where he needs help.
"Being 38 he never expected the news we received about his stage four cancer and after chemo he thought everything was ok.
"It's really taken care of, and at this moment in time needs to be home, surrounded by loved ones and receiving the medical attention he deserves and needs.
"He is still constantly vomiting and unable to keep down fluids or food.
"The only thing keeping him alive is the drips he is on as he has no other way to get the proper nutrients and energy he needs.
"He has not drank or eaten food in over two weeks."
Mr Park said it was struggling to understand what it was wrong with.
Mr McAllister had not received his final scan results.
He said: "His half-way scan showed chemo was working and the 'stock left behind after his tumor was removed were shrinking.
"We asked so many times if this holiday was ok and we were just told to go there, there was no reason we should not go on holiday."
Karen Bell, who set up the fundraising page.
She said: "We're desperate to get Jon Paul home to get the best treatment possible."