Dave Sharp was the first person in Scotland to win compensation from a Catholic order in August for ordeals suffered at St Ninian’s residential school in Falkland when he was 10 years old.
He said he had experienced “addiction and imprisonment” in a life framed by his adverse childhood experiences.
“Given the lack of help from Scottish politicians I am particularly disappointed with Kezia Dugdale, who while still Labour leader in Scotland gave me an understanding she’d do everything she could.
“I met her at the BBC studios earlier this year and she told me that she 'had been doing everything she could and she would continue to push the Scottish government to help more survivors to come forward,’” Sharp told Holyrood.
“I’ve dealt with my anger, I forgave my abusers, but this actually hurts.”
The Scottish Child Abuse inquiry chaired by Lady Smith is currently undertaking public hearings.
Sharp said there was “no publicity whatsoever about it”, that the Scottish Government has engaged with less than one per cent of abuse survivors in Scotland ahead of the hearings and has not encouraged others to speak up.
The inquiry in Northern Ireland has seen 500 victims come forward, compared with around 300 in Scotland, he pointed out.
However during a series of public protests by Sharp, including a similar vigil during the independence referendum week in 2014 and chaining himself to a cross outside St Andrew’s cathedral in Glasgow last year, he said he had been approached by “hundreds of survivors”, including one who had travelled from Dundee this week to speak to him.
“People don’t have confidence in the politicians because there is no evidence they will be believed or looked after if they do come forward,” he said, “they’re drowning in a sea of abandonment”.
Deputy First Minister John Swinney and a number of Labour MSPs have come out to speak to Sharp this week, he said, but added it had looked like a number of SNP MSPs had avoided him.
“It felt the exact same as the Catholic church,” he said.
Speaking from Australia, Dugdale's spokesman said she "fully supports the Scottish Child Abuse Inquiry and all efforts being made to support survivors of historic abuse".
Labour's education secretary Iain Gray "has met with Mr Sharp a number of times," he added, "and continues to engage with him and his organisation, S.A.F.E".
“Kezia Dugdale is committed to be being an open and accessible MSP and will be hosting public advice surgeries in the Scottish Parliament for constituents following her return to Edinburgh."