ET's Nischelle Turner was at the Christopher and Dana Reeve Foundation fundraising gala in New York on Thursday, where she spoke with Zak about how he and his family have been holding up three months after Robin's death.
"We're doing okay. We're working hard to build our strength and acclimating to the new normal," Zak, 31, told ET. "A large part of what we're doing through this grieving process is giving and spending time focusing on others."
Friends and fans across the globe were devastated by the legendary comedian's death, and many took to the web to share memories, express their grief and send condolences.
"The outpouring was remarkable," Zak said, smiling. "People shared their supportive words, art, and all sorts of amazing tributes to my father."
Robin's son attended the fundraising gala to take part in honoring his father, and celebrating his friendship with the late actor Christopher Reeve.
Nischelle Turner even showed Zak a video from the ET vault, which was an interview with Robin and Christopher from the early 1980s.
Check out the video for more of Zak Williams sharing memories of his father's long relationship with Christopher Reeve, and to hear part of his tribute speech from the gala.
Zak's sister Zelda recently got a tattoo in memory of her father. Check it out, below.