The star, best known for his role on soap opera EastEnders, was hospitalised on 30 January after his Mini Cooper vehicle smashed into a steel barrier in Derby, England.
He has now spoken for the first time about the horrific accident, revealing the car's airbags did not deploy because he wasn't wearing his seat belt. He smashed his head on the steering wheel, leaving him with a huge gash on his forehead which had to be stitched up by doctors.
Gaffney insists he was terrified as he was cut free from the wreckage of the crash, and feared he would be left brain damaged by his head injury.
He tells The Sun newspaper: "I'm an idiot. I should be dead... I wasn't wearing my seat belt so the airbags didn't go off and I smashed my head into the steering wheel... I was hysterical... I was crying like a baby and pleading with the paramedics to save me... I was covered in blood and I just kept saying... 'Don't let me die, please don't let me die'...
"They were saying: 'We know you've had a bad head injury...' I just panicked... I feared the worst. I though, 'That's it. I'm brain-damaged.'"
Gaffney did not suffer brain damage, but he has been left with a nasty scar and he admits fearing the injury could have cost him his acting career: "I kept thinking, 'Oh my God, my career is my face.' I was scared my injuries would have disfigured me so much my acting career would be dead.'"