Robin was found dead in his home in 2014 after taking his own life, and, taking to social media, the actress explained the difficulty she had getting condolences from anonymous fans while marking her father's death.
"Tomorrow is Dad's death anniversary," Zelda began. "As always, I will not be here. It's hard for me on regular, good days to remain the person expected to graciously accept the world's need to share their memories of him and express their condolences for his loss."
The "Detention" star reiterated that she appreciated messages about her father, but confessed that "some days it can feel a bit like being seen as a roadside memorial - a place, not a person - where people drive past and leave their sentiments to then go about their days comforted their love for him was witnessed."
"Sometimes, that leaves me emotionally buried under a pile of other's (sic) memories instead of my own," she continued. "After all, even roses weigh a ton when they're left by the truckload."
Adding that the day would be "simply too much" for her to bear, Zelda also included information for suicide prevention and substance abuse hotlines for countries throughout the world for those affected by similar issues.
"Whoever out there needs to hear it, please use this as your signpost in the desert," she wrote. "Reach out. Seek help. Keep fighting."