Dutch national Mark van Dongen, 29, was left with 80% burns and paralysed after being attacked in Bristol in September 2015. He died earlier this month.
Speaking about his father Kees, who speaks little English, Mr van Dongen's brother Bartje said "once my dad was a very big man, now he is broken".
A woman, from Redland, denies offences related to throwing corrosive fluid.
Berlinah Wallace, 46, is due to face trial in April.
Mr van Dongen was from the Netherlands but was working as a civil engineer in Bristol.
He was injured on Ladysmith Road in September 2015 and died in Belgium on 2 January this year.
He spent two months in intensive care at Southmead Hospital before being moved to its burns centre.
Friends of the family eventually raised money for a private ambulance to take him to a hospital in Belgium, where his father now lives, in November 2016.
Speaking about the immediate aftermath of the incident, Bartje van Dongen said his father drove to Bristol from Belgium every weekend, sleeping in his van in freezing temperatures.
He said: "Mark felt a lot of pain, his eye was gone, his nose, his ear, his leg.
"On the arm all the muscle was gone, his bone was slowly being eaten away by the acid.
"My dad sat by his bed 22 hours a day scratching him and moving his arms to try to take the pain away."
The family said they were upset with Avon and Somerset Police, after it took the force more than a week to contact the family after the attack - meaning Mr van Dongen was alone for nine days.
A police spokesman said it was hard to trace his next-of-kin.
The Dutch Association in England is fundraising to bring the family over for the trial.
The death of a man who was attacked with acid has left his father "broken", according to the family.