Jonathan Ellis, of Front Road, Woodchurch, was on the wrong side of the road when he smashed into Pat Ireland's Jaguar on December 29.
The 25-year-old escaped serious injury, but 59-year-old Mrs Ireland has been left disabled and unable to work since the accident.
Ellis admitted causing serious injury by dangerous driving - an offence that only became law in the month of the crash.
He was today jailed for two years at Canterbury Crown Court and banned from driving for eight years.
Addressing the court, mother-of-two Mrs Ireland told how her life had been ruined "because of five minutes of what this idiot did".
Judge Nigel Van Der Bijl told Ellis: "This was an extremely bad manner of driving. People should realise that when they are driving a car they are driving something which can kill. I cannot possibly suspend this sentence."
Trevor Wright, prosecuting, said care home manager Mrs Ireland was driving in Trinity Road, Ashford, at about 11pm on December 29 after having picked up a fast food meal for her staff from the Eureka Leisure Park.
"She was heading home and as she took a turning off a roundabout she noticed four headlights coming towards her," he said.
"One set was on the right side of the road and one set, on a car driven by Ellis, was on the wrong side of the road. There was a head-on crash."
Pat Ireland was left disabled after a head-on car crash
Mr Wright said firefighters had to take the roof off Mrs Ireland's car to get her out. She received "devastating" injuries and is still taking morphine for the pain.
There were two passengers in Ellis's Nissan Almera car and they told police he was racing to get past a vehicle in front of him.
Mr Wright said: "They speak of extreme speed and braking and this came to its tragic end when the vehicle in front braked and Ellis was too close to stop. His car skidded into the path of Mrs Ireland."
In a statement, one of the passengers said: "It makes me so angry. If Jon hadn't been driving like this none of this would have happened."
The other passenger said he just remembered feeling "very scared".
Driver Pat Ireland's Jaguar was left badly damaged
"I keep remembering that lady's face, covered in blood and her screaming in pain," his statement said.
Despite a serious head injury and being in terrible pain from a badly broken ankle, Mrs Ireland was able to phone for help from her car phone - which was on speed dial to the St Valery care home she had run in York Road for 22 years.
Her husband, Jim, and other family members were on the scene within just minutes.
Tearful Mrs Ireland today told the judge her life had been ruined as a result of the crash with Ellis's car.
She spoke of her sadness at no longer being able to run the care home, which has been taken over by daughter Sam.
She said: "I had built up my care home business for 23 years and now I have lost that because of the brain damage I have."
The stitches to Pat Ireland's forehead after she was in a head-on collision with Jonathan Ellis
Fighting back tears, Mrs Ireland went on to tell the hushed court: "I cannot drive. I cannot do anything. I have to go to a clinic for brain injuries each week to try to get it working again.
"I cannot walk and my whole life has been turned upside down because of what he did. It is not fair.
"I have a brace on my leg which will be there for ever. I feel lucky to be alive, but my life is very different.
"I cannot walk and my whole life has been turned upside down because of what he did. It is not fair..." - Pat Ireland
"I have been a prisoner in my own home for more than four months because I can't get out.
"My grandchildren do not have the nana they had before and my husband does not have the wife he had. It is not fair just because of five minutes of what this idiot did."
The mother-of-two and grandmother-of-six was in hospital for 16 days recovering from a compound fracture to her right ankle, two skull fractures, front lobal brain damage, two broken verterbrae in the neck and eye damage resulting in a cataract.
She has also been diagnosed with post traumatic stress disorder.
Mrs Ireland has undergone two operations on her right ankle and earlier in her treatment there was concern she might need her foot amputating.
She has to wear an ankle brace permanently as she has no tendon support to the ankle joint. She has been left permanently disabled and will have to walk with a crutch.
The scene where Pat Ireland's silver Jaguar was hit by Jonathan Ellis's Nissan Almera at Trinity Road, Ashford
Dan Pawson-Pounds, defending, said Ellis could not remember what happened - but accepted he was driving dangerously after what his passengers said.
"He was racing the four-wheel drive vehicle in front," Mr Pawson-Pounds said. "He was reckless in his behaviour, but he did not intend to cause what happened. He shows a great deal of remorse."
Mr Pawson-Pounds argued for a suspended sentence and said Ellis, who works for a poultry farm, acted out of character.
Judge Van Der Bijl also ordered Ellis to take an extended driving test before he gets his licence back.
After the hearing, Mrs Ireland said she was very happy with the sentence.
"I am pleased with the outcome as I expected he would only get a few months," she said.
"If he had only said sorry to me, even with a letter or card, but he has said nothing to me."
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