Robin Thicke is trying to be strong for his family.

The "Blurred Lines" singer has started making funeral arrangements for his beloved father, Alan Thicke, who died at age 69 on Tuesday after suffering a heart attack while playing hockey at a skating rink in Burbank, California.

WATCH: Robin Thicke Remembers Late Father Alan Thicke As 'The Greatest Man I Ever Met'

A source close to the family tells ET that Alan's surviving wife, Tanya Callau, "is beside herself," and Robin, 39, has "really stepped up" as friends and family began traveling to Los Angeles on Friday for the upcoming memorial service.

"[Robin's] realized that he has to be incredibly strong for his family right now," the source continued. "He is focused on honoring his dad, and making this easy on his family."

According to the source, Robin has been personally arranging all travel for out-of-town family members, securing local hotels and even offering to let them stay at his home.

"He's planning a tribute to his dad and has been personally calling some of his dad's Hollywood friends to get stories and quotes," the source added. "He knows he has to be strong for his brothers, and is focused on making this as easy for Carter as possible."

WATCH: Inside Alan Thicke's Wedding to Tanya Callau and a Look Back at Their Love Story

In addition to Robin, Alan and his first ex-wife, Gloria Loring, also share 41-year-old son Brennan. Alan also had a son, 19-year-old Carter, with his second ex-wife, Gina Tolleson.

ET spoke with Gloria over the phone from her home in Lake Arrowhead, California, on Wednesday, where she reflected on some of her most precious memories with the Growing Pains actor.

"[Alan] loved his family so much," Gloria explained. "He was the centerpiece to our family and I can't imagine going forward. We always had Thanksgiving and Christmas with the big, extended family, and I just can't imagine how it's going to be without him."

"Alan loved his kids, loved his grandkids -- he was known as 'Pops,' and I think my son could speak best to their relationship with him, but I know it was always one of a mentor, a counselor, a supporter," she continued. "He was always there when they needed him. He was very devoted to his family and he was always so much fun to have in the room anywhere he was -- his sense of humor went before him."

WATCH: Gloria Loring Reacts to Death of Ex-Husband Alan Thicke