Janette Robertson, 65, from Forfar, won the money in the EuroMillions Millionaire Raffle on July 26.
She has worked in Hampton's newsagents in the town for 18 years and planned to retire later this year. She has now brought the date forward since becoming a millionaire.
He first purchase was a Mini and she is planning a family holiday with her husband Dennis, who also retired after the win, her children and grandchildren.
Mrs Robertson realised she won when she checked the raffle code at he start of her shift the day after the lottery draw, leaving her in "utter disbelief".
She said: "My boss Ian had printed all the winning raffle lines off so I checked my ticket against them. When I saw that my number matched I read it a few times to make sure then called Ian through. I made him read it out to me twice and it was only when he checked it on the machine and it confirmed I was a winner that I really started to believe it."
Mrs Robertson is one of 100 winners of the raffle draw, each winning £1 million, and she plans to continue buying weekly tickets.
"Winning has given me the independence to really enjoy my retirement. But I still buy my tickets every week, although when I go to the shop to put them on, they joke that they're not going to put them through as I've already won."