Does anyone know my father John Cole. ?

My father John Cole served in the 2nd world war. We believe he was a gunner in the airforce. He was admitted to a mental institution in or very near St Albans in the early 50’s. My family never spoke of him. My grandmother who was very religious said he was an evil man. I believe he was suffering from PTSD. I would like to know more about him and if anyone remembers him or how I can find out more about my father. I don’t even know his date of birth. He married my mother Dorothy Cole nee Parker and they lived at 7 Tempest Avenue Potters Bar. My father died in the mental institution in about the mid 60’s. I am now a great grand mother and would like to know about my father and to be able to tell my family about him.