Rachael Pogois, vice-chairwoman on the council of St Andrew's International Church in Athens, said she was "very, very concerned" about the upcoming levels of austerity which would come with the financial deal.
She was speaking after Eurozone leaders agreed to give Greece a third bailout package of up to €86bn over the next three years, in exchange for further austerity and reforms.
Eurozone leaders refused to write off any of Greece's debts, despite calls from some to do so.
Talks between the two parties lasted 17 hours before a deal was struck.
The money will mean Greek banks will be able to reopen after two weeks of closure, and that capital controls - where people have only been allowed to withdraw €60 per day - will be lifted.
Some analysts had predicted Greece's economy would have collapsed without another bailout.
Greece is €320bn in debt, a ratio of 177% to their GDP, and around 1 in 4 Greeks are unemployed. Greece's GDP has also fallen by a quarter since 2010.
The Greek government still has to pass the new bailout deal for it to come into effect.
Greek Prime Minister Alexis Tsipras, pictured, said the deal meant Greece had "managed to avoid the most extreme measures".
In exchange for up to €86bn, it will have to reduce pensions, raise taxes, and sell off some state-owned assets.
Rachel Pogois told Premier's News Hour: "Oh, we're very, very concerned [about the upcoming austerity], very concerned. It is devastating for many, many people. It's across the board. It's not just one group or another group, it's all people who live in Greece.
"Many people realise that we have no other choice. Of course the banks are still not open, people are really beginning to suffer I think.
"It is very difficult to live on such a reduced amount of cash. A lot of people, their salaries are paid through the banks, they cannot get them out except 50 or 60 euros a day. It is very, very difficult for people and they're just trying to make do as long as they can."
Listen to Premier's Antony Bushfield speaking to Rachel Pogois here:
