Billy Bob Thornton, acclaimed actor and award-winning director, recently opened up during an interview with Juju Chang on ABC’s “Nightline”. During the piece, Thornton admitted that it was his own inherent insecurities that ultimately resulted in the destruction of his marriage to actress Angelina Jolie. During their relationship, the duo was deeply dedicated to one another, going as far as to wear vials of each other’s blood around their respective necks.

“I blew it because I didn’t think I was good enough for her. She has one way she wanted to live her life and I had another way to live mine and I was just too insecure,” Thornton explained.

The actor, who originally began his career as a country singer, touched on a number of different subjects, many of which are covered in Thornton’s book “The Billy Bob Tapes: A Cave Full of Ghosts”. He also addressed the way he gains and loses weight for roles, often to the extreme. In one instance, Thornton lived off of a can of tuna and Twizzlers in order to appear “gaunt”. The same method was used by Christian Bale for “The Machinist”, thought the Caped Crusader substituted an apple in place of the twisty red candy.

“If you want to [lose weight] quickly, you just pick something and because I happen to know if you eat a can of tuna and a pack of Twizzlers, you will lose weight, I promise you,” Thornton said.

Thornton speaks frankly about his marriage to Jolie in the tome, addressing numerous rumors that plagued the couple for years. For instance, did the pair really live in a dungeon during their brief union. The answer, unfortunately, is a resounding no. However, there appears to be very little bad blood between the two; Jolie penned the forward for the book, in which she fondly reminisces about the time they spent together.

“The Billy Bob Tapes: A Cave Full of Ghosts” arrives in bookstores today (May 15th). You can catch the full interview with Thornton tonight at 11:30 on ABC.