Adam Beardmore, 42, had been driving home to Matlcok from Nottingham when police pulled him over around 8.50pm on May 30.
Prosecutor Pardeep Kalyam told Chesterfield Magistrates Court after failing the roadside breath test Beardmore blew 91 micrograms of alcohol in 100 millilitres of breath at the police station.
Mr Kalyam said the defendant had two previous convictions for excess alcohol in 2001 and 2004.
Julie Page, mitigating for Beardmore, said her client was “fully cooperative” both at the roadside and the police station.
She said: “He was a chef by trade at the time and is candid in saying since losing his father aged 11 he had drunk regularly from the age of 14 - he describes himself as alcohol dependant.”
Ms Page said Beardmore had been using alcohol as an “emotional crutch” following a recent separation from his wife.
The defendant had consumed “quite a bit of alcohol” the previous night with a friend in Nottingham followed by “a few drinks” after work the following evening.
Beardmore’s solicitor added: “He is a functioning alcoholic and had no real sense of how much he had to drink.
“He has to accept it’s luck rather than judgement that he is not before the court with more serious charges.”
Ms Page said Beardmore had lost his job as a result of the incident and was now looking to change careers.
The defendant, of Cavendish Road, Matlock, admitted drink driving.
He was banned from driving for 24 months, fined £120, handed £85 court costs and a £95 victim surcharge, 15 rehabilitation activity days and a six-month alcohol treatment requirement.