Susan Sarandon's actress daughter Eva Amurri Martino had a heartbreaking end to 2016 after a nurse dropped her son Major on his head and fractured his skull.

The Saved star has detailed the horror following the accident in a post on her HappilyEvaAfter website, revealing it happened at the end of November (16).

A nurse hired to look after the three-month-old and his two-year-old sister Marlowe Mae overnight fell asleep while holding Major and dropped him on his head.

Eva and her husband Kyle Martino were awoken by the thud of their son hitting the hardwood floor and his "hysterical piercing screams".

"He suffered a fractured skull and bleeding on his brain, and was transported by ambulance to Yale Medical Center where I spent two harrowing days with him to receive emergency care and further testing," the actress reveals. "To say these were the most traumatic and anxious two days of my life is an understatement."

But little Major survived the scare and has been "healing well" and "hitting milestones".

His relieved mom reveals he is "cooing, smiling, and generally showing us that he is and will be ok as he grows and develops".

Amurri Martino admits she waited a month to open up about the scare because she feared people would frown on the idea of her hiring a night nurse to take care of her kids when she was asleep.

"Let me tell you, the guilt I bore in the days and weeks after this accident was more intense and more damaging than anything I would wish upon my worst enemy," she writes. "I wept in the hospital, telling anyone who would listen that it should have been me. That I was to blame.

"Even though I finally made peace with the fact that this freak accident could not have been avoided by me, it has continued to effect me to my core and in all aspects of my daily life."

"It's nearly impossible for me to trust anyone but myself to take care of Major now," she added. "Hearing Major cry hard immediately triggers my memories of the moments after the accident and instigates an immediate panic attack - my heart races and tears spring to my eyes."

And now Eva is a mom on the edge during trips to the park with her daughter - something she realized during a recent day out when little Marlowe fell over and started crying.

"Within ten minutes she was totally fine and normal - but I stood there while Kyle held me, sobbing and shaking, while my scared two-year-old watched," she wrote. "I think I need to take some things off of my plate. It's time to really face this all and find a solution."

The actress is now seeking help from a therapist to help her combat "some form of Post Traumatic Stress Disorder, possibly linked to some form of Postpartum Depression".