United Kingdom, May 11 -- David Morrissey was in a "terrible state" as he battled alcoholism.

The Walking Dead star - who has been sober for 21 years - has confessed his drinking spiralled out of control after he used alcohol to help him cope with bouts of "social anxiety" and the trauma he suffered following the death of his father when he was a teenager.

During an appearance on BBC Radio 4's Desert Island Discs, Morrissey explained: "I am a recovering alcoholic. Drinking first was about anxiety. I've had this terrible social anxiety and that helped me get through it ...

"Later on in my adult life, I couldn't stop. I wasn't drinking to be convivial. I was on my own in the pub. That was really hard and very hard for my ex-wife and peop...