Amber Portwood took to Twitter this week to announce the passing of her father, who had undergone surgery for his liver and was put into a medically-induced coma at one point.

Portwood’s brother, Shawn, told The Daily Mail that their father had been sick for some time, but no one expected him to pass away so suddenly.

“My dad was the most important person in Amber’s and my life. He was a very strong-willed person and even though he was battling illness for a very long time, he never gave up. He didn’t give up on life. He didn’t give up on his family. He didn’t want to give up,” he said.

Shawn Portwood also said that their father helped the Teen Mom star tremendously on her road to recovery and in trying to stay sober when she was released from jail.

“I know that he helped Amber because he gave her strength to get better. He is the reason she was able to turn her life around. He set the precedent for what she needed to do to get better,” he said.

Amber has not released a public statement but did take to Twitter to thank her fans for reaching out to her during such a hard time for her family.

I just want to say thank you to everyone for all your kind words.This is a heartbreaking time for my family your prayers help..love always

— Amber Portwood (@AmberLPortwood) December 18, 2014