“[We’re doing] as good as we can,” David, 53, told Robin Roberts on Good Morning America Wednesday. “It’s been very tough, obviously. It is very sweet that everyone came out of the woodwork, that she made an impact.”
During the interview, David looked back on his relationship with Kate over the years, and shared a sweet story of how his former girlfriends would “bring their A-game” and dress to impress the designer when they visited her.
“It’s funny, ’cause every girl I was with or anyone that knew they would see Katie would dress differently,” he said. “They would bring their A-game. It was very sweet. They would be like, ‘Is Katie coming? Is Katie gonna be there?’ And if [she was], it was a whole new wardrobe.”
David continued, “Katie was very sweet. She knew that they were doing that, and then she would … compliment [them]. And when I’d say, ‘You don’t dress up for me!’ they’d go, ‘Yeah, that’s her and you’re you.’ She was such a beautiful, lovely, great spirit that obviously will be missed…I’ll start bawling.”
David paid tribute to his late sister-in-law with an Instagram post hours after news of her suicide was made public.
“Fuzzy picture but I love it. Kate and I during Christmas family photos. We had so much fun that day. She was so sharp and quick on her feet. She could make me laugh so hard,” wrote David, brother of Kate’s husband of 24 years and Kate Spade New York co-founder, Andy Spade.
“I still can’t believe it. It’s a rough world out there people, try to hang on,” David added.
In a second tribute on Twitter, he wrote, “Katy at my book signing. I love this pic of her. So pretty. I don’t think everyone knew how f–king funny she was…”
David then honored Kate by making a $100,000 donation to the National Alliance on Mental Illness (NAMI) — the nation’s largest grassroots mental health organization dedicated to building better lives for the millions affected by mental illness through educational programs and support groups.
“More people suffer from mental health issues than we may realize but no one should ever feel ashamed to reach out for support,” David said. “If you or anyone you know is in need of help or guidance please contact the national suicide prevention hotline at 800-273-8255 or go to nami.org to learn more and help those who may be in need.”
RELATED VIDEO: David Spade Breaks His Silence After Sister-in-Law Kate Spade’s Death: ‘I Still Can’t Believe It’
On June 5, Kate’s family, friends and fans were shocked to learn a housekeeper arrived to find Kate alone and unresponsive in the bedroom of her Manhattan apartment. The New York City’s medical examiner’s office officially declared the designer’s death a suicide two days later.
Her husband, Andy, revealed on the day of her death that Kate had been in treatment for depression and anxiety. He also confirmed the couple’s separation, noting that he had moved out 10 months earlier to an apartment several blocks away, where daughter Frances Beatrix, 13, spent half her time.
Kate’s loved ones continue to honor her legacy while trying to understand the pain that led to her death. “We knew Kate had her problems and demons,” one friend told PEOPLE. “But no one would have ever expected her to do this.”
If you or someone you know is considering suicide, please contact the National Suicide Prevention Lifeline at 1-800-273-TALK (8255), text “help” to the Crisis Text Line at 741-741 or go to suicidepreventionlifeline.org.