AceShowbiz - It's not often we hear a Hollywood star candidly discuss their struggles with parenthood and addiction. In his new memoir, "Runaway Train: Or the Story of My Life So Far," Eric Roberts does just that, sharing his poignant journey of being a father to actress Emma Roberts.

Eric, best known for his roles in "Star 80" and "The Dark Knight", offers an unfiltered look at his life, particularly his experience with fatherhood. In his memoir, Eric reveals the difficulties he faced parenting after he and Kelly Cunningham, Emma's mother, separated.

"I had abandoned Kelly when Emma was just seven months old," Roberts writes. "We went through a lot, and [Kelly] saw me at my absolute worst - yet she stayed, for a time, though I'm sure she questioned whether or not she should. We both wanted a child - maybe I did more than she - but we both wanted to become parents."

His candid reflections highlight both joyful and challenging moments from Emma's early days. He recalled trying to induce labor to align with the due date, singing "Happy Birthday" to his unborn daughter, and the overwhelming love he felt the first moment he saw her.

However, Roberts also confesses he was ill-prepared for the responsibilities of fatherhood. Despite his strong love for Emma, he struggled to adjust to the realities of having an infant, compounded by his drug addiction.

"I loved my little daughter with the strength of Hercules, despite my own weaknesses," he admits. "However, I couldn't handle the realities of an infant coming into my life, and I couldn't handle being a parent! I'm still not a father figure."

Roberts attributes his parenting struggles largely to his drug addiction, which he says led to losing custody of Emma. "The biggest consequence of my drug use was losing Emma," he reveals. "I was still impossibly coked up when she was born, which explains everything."

He clarifies misconceptions about a supposed custody battle with Kelly Cunningham, stressing that he never sought physical custody. "I never saw myself as someone who deserved to have physical custody of Emma, not in a million years."

The memoir also dispels rumors about a fallout with his famous sister, Julia Roberts, over Emma's custody. Instead, Julia supported him financially during the separation's legal proceedings and remained hopeful that his role as a father would bring stability.

"My sisters were hoping that my having fathered a child that I loved with the woman I was with would maybe calm me down and make me more stable as a person. Unfortunately, the stability has to come first. It's not a child's job to make you stable," he reflects.

While he acknowledges that both Julia and Emma have surpassed his own fame, Eric takes pride in their achievements and feels grateful for the support they have provided. "I imagine I will remain as Julia's brother and Emma Roberts's dad for the rest of my life. I'd like to make good on that, to move aside proudly and with grace. That's part of the reason for writing this book."

Eric Roberts' memoir, with its heartfelt and unvarnished storytelling, underscores his journey and ongoing efforts to reconcile with his past. "Runaway Train: Or the Story of My Life So Far" is available now and is a compelling read for anyone interested in the complexities of family, fame, and personal redemption.