Boyle, who found fame on Britain’s Got Talent, said she still struggles to come to terms with her traumatic childhood,
Her dad Patrick was a miner and also fought during World War Two.
He died in 1997 age 81 and Boyle said she still considered him a good man, despite his violent relationship with her.
The West Lothian singer, 55, said: “My father, though a very good man, had a temper.
“He showed it to me and he hurt me.
“He didn’t mean to, but I held onto this for years - and when he was dying, I had to let it go.
“You have to accept it, that’s maturity,” he said.
The singer, who shot to fame in 2009, said she still struggles to come to terms with her past.
She said: “It’s not easy, but you have to let it go and replace it with a new self. I’ve a lot of good and bad memories. All these things that happened in my life, you have to let go of the bad.”