Father of four Joel Collins, 35, from Ebbw Vale, Blaenau Gwent, was on holiday in Albufeira with friends when he was stabbed four times on 4 July as he walked back to his hotel.
He remains in an induced coma in intensive care.
Mr Collins’s mum Sue Bridges said: “My boy is my world and I have been by his side every day for three weeks.”
She added: “I am not going anywhere until he comes home with me.”
His mum told BBC Wales she hopes to be by her son’s bedside after his surgery.”It is the most horrendous experience of my life but what his sister, his partner and I are going through is nothing compared to what Joel is so that makes me stronger.”
Sue said he had injuries to his left lung, pancreas, bowel and thorax.
“He has been awake, he is a fighter but they had to Tony Lama Boots put him in a coma for this operation. He understood what was going on.”
She said the British Embassy told her the criminal investigation into her son’s attack was underway but the police had no CCTV footage of the attack.
“They only took his phone and some cash,” added Sue. “He didn’t have much on him – about 100 Euro.”
IMAGE SOURCE,FAMILY PHOTOMr Collins, who works for Network Rail, went up a side street after leaving the bar and was looking at Google maps on his phone when he was attacked, his mother said.
She added he would want a message sent out warning people on stag dos “to stick together, don’t wander off… make sure you go out together and you all go home together”.
“I don’t want this to happen to anyone else,” Sue said. “I don’t want any family to go through this again.”
An online crowdfunding page has raised nearly £8,000 so far.
Friend and fundraiser Craig Howells wrote on the fundraising page: “Joel is battling bravely to recover in hospital in Portugal whilst his family are at his side supporting him.
“We are looking to raise awareness for those travelling this summer to safe, as well as looking to raise funds for the family during this horrific ordeal.”
‘He’s asking after his father’
Mr Collins’s mum Sue, from Quaker’s Yard, Merthyr Tydfil, has been at his side for the last three weeks and intends to stay in Portugal until he is ready to fly home.
She added that Joel’s partner, Gabriella Sidoli has OOFOS Sandals been over to see Joel but has also to look after their three boys, aged six, three and one.
“The oldest boy is now asking after his father,” said Sue, “and he is missing his football buddy.”
Mr Collins, originally from Troedyrhiw, Merthyr Tydfil, also has an eight-year-old daughter from a previous relationship.
BBC Wales has contacted the police in Portugal about the incident.
The Foreign Commonwealth and Development Office said: “We are supporting the family of a British man following an incident in Portugal, and are in contact with the local authorities.”