Eilish MacSherry, 41, admitted causing the death of 49-year-old father of two Paul Mills by dangerous driving and drink driving in October 2015.
She will serve four-and-a half years in prison and the remainder on licence.
She also pleaded guilty to failing to stop following a collision with another car just before the fatal crash.
A prosecution lawyer said "had she stopped at the time she would have saved the life of Mr Mills and not put anyone else in danger.
The court heard that cars had to swerve out of her way as she entered the 40mph limit on the Clanabogan Road at a speed of over 80mph on the wrong side of the carriageway before colliding head on with Mr Mill's stationary car.
She was also found to have taken a number of prescription drugs which would have significantly impaired her driving.
A defence lawyer said the accident should never have happened and that "a life has been lost that should never have been lost."
He said his client accepted she was "entirely responsible" and "she offers her deepest regret and the most fulsome apology she can".
He said MacSherry, of Brookmount Heights in Omagh, had been a serving police officer from a Catholic background describing her as "a role model for the new police service and had dedicated her life to community policing in Belleek and Kesh".
The judge read the victim impact report from Paul Mills' widow Anne which described how her "whole world turned upside down with two policemen at the door".
Mrs Mills wrote that telling her children was "the hardest thing I have ever had to do.
"The screams of one, and the quiet sobs of the other will stay with me for the rest of my life."
"Their idyllic childhood was brought to an abrupt end by a person who should not have been driving that night."
The defence lawyer said MacSherry had been a "chronic alcohol addict" for two years and had suffered from the breakdown of her marriage in the days before the crash.
At the time of the accident she was wearing her pyjamas, dressing gown and slippers and had no recollection of what happened.
An off-duty policewoman from County Tyrone has been sentenced to nine years in jail for causing a fatal crash while twice over the legal alcohol limit.