My dad is having a rough time..how can i help him?

Ok when my dad was growing up he never knew his real dad his real dad was always in jail or never around.His real dad even beat my gma(my dads mom) whiile she was pregnant with him We are still close to some of the relatives on that side of the family and my dad was invited to the wedding. My dad had so much he wanted to ask his real father about why he would do that and why he wasnt in his life. My dad met his real father at the funeral about 13 years ago and his dad was the man in thje casket my dad found out he has a brother and sister who his father was involved in their lives. He was suposed to ask his real fathers best friend a lot of questions and found out hes dead to. Fathers day this year was really hard on my dad and i havent really talked to him since hes not eating normally always sad . My dad lost his younger brother to suicide. His brother was 14 years old this was about 10 years ago. i jsut want to know how to help him and show him i love him and i appreciate him in my