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.