Nicola Bulley's dad says the family are waiting for a "breakthrough" as today marks three weeks since she went missing.
The mortgage adviser, 45, was last seen on January 27 while walking her springer spaniel Willow in the village of St Michael's on the Wyre in Lancashire.
Police launched a massive search for the mum, using drones, dogs, and specialist divers and expanding more than 13 miles to Morecambe Bay.
Ernie Bulley, 73, says "every day is a struggle" as the family are desperate for answers.
It comes one day after, Nicola's family released a heartbreaking directly appealed to the mum, saying to "not be scared" as her girls "want a cuddle".
Today, Ernie told Sky News: "Every day is a struggle. [We're] no further on from three weeks ago.
"[We] just need a breakthrough to give us some hope."
It comes after Nicola's sister shared a sunny snap of herself with Nicola and their mum Dot, 72 on her Facebook wall today.
She wrote: "Three weeks today without you home. We all miss you so much, time to come home now."
Yesterday, her parents returned to a bridge near the scene where she vanished, and told their daughter: "We pray everyday for you".
Two new messages had been penned on yellow ribbons of hope, attached to a bridge near the footpath where Nicola was last seen.
They were left by Nicola's parents, Ernie and Dot and her younger sister Louise.
The message from her parents read: "We pray every day for you. Love you, mum and dad xxx"
Another from her sister said: "Nikki, please come home. I love you, Lou xxx"
This week, police held a press conference where they said for the first time that the mum-of-two was categorised as "high risk" due to "a number of specific vulnerabilities".
At the time, they did not elaborate and sparked further speculation despite trying to use the press conference to squash any unhelpful theories.
Hours later, the force stated on Facebook that Ms Bulley "in the past suffered with some significant issues with alcohol which were brought on by her ongoing struggles with the menopause".
They added that these issues had "resurfaced in recent months".
The family have since clarified that they were aware that these details would be released.
In a statement released yesterday, they said: "Despite what some media outlets and individuals are suggesting, we are being updated daily and receive support from our family liaison officers."
They added: "Nikki is such a wonderful daughter, sister, partner and mother and is missed dearly - we all need you back in our lives.
"Nikki, we hope you are reading this and know that we love you so much and your girls want a cuddle. We all need you home. You can reach out to us, or you can contact MissingPeople.org.uk. Don’t be scared, we all love you so very much."
