The Ministry of Justice has given the charity - which supports people affected by neurological conditions such as multiple sclerosis, Parkinson's, ME and motor neurone disease - until the end of June to vacate its home next to the prison.
Charity founder Sharon Jackson said they have now launched a fundraising page and are asking local tradespeople to get in touch if they can help.
"Lancaster Farms need the building back," Sharon said. "There's a potential to extend until the end of August but no guarantee.
"We have got to find somewhere else. We are dealing with a situation where this is a lifeline for people, and if it closes where will they go to get the support they get here?
"When the charity first started we were in Sainsbury's cafe, but with the way it's grown we can't do that now.
"We have had the support of the Ministry of Justice for seven years but this is a government directive and we need to move."
Sharon, 61, said she is now appealing to local residents to support the charity.
"Our challenge is to persuade people that they can help us," she said. "They don't need to donate money, it could be someone with some spare land that we can build on, or someone who can donate their time or materials.
"We are a good community and there's a lot of love for our charity and we can do this.
"We are looking for our forever home."
Sharon, who has multiple sclerosis, said the charity provides vital support to numerous people living with neurological conditions, as well as their families.
"It's like a family," she said. "For people who are on their own and don't have any other support, we are a lifeline.
"People are free to come here and not be judged and some of them are frightened now that they will have nowhere else to go.
"I never thought it would get like that but it has and I know the responsibility is huge. It feels like I am making my family homeless."
Anyone who can help the charity can go to their new online fundraising page here"It's a doable project but we need to get the community behind us," Sharon added.
"We are doing something completely different from any other charities around here - let's not lose this fantastic resource."