I haven’t had a bunny that afraid but our rabbit was very skiddish when we first got her from the shelter.
We gave her a lot of her own space, let her approach us, and over time, she started realizing we were nice and the ones giving her food…once a bunny knows you as the barer of food, they get friendly! We then would approach her with things like fennel, a treat like fruit or a carrot, mint leaves, etc.
She now only gets timid around new people and hides unless they give her something as a peace offering! Once they feed her, she’s happy as can be!
We also avoided picking Willow up because that’s where a lot of her fear seems to stem from. To this day, we don’t hold her and she’s now comfortable flopping stomach side up directly in front of us. She has full run of our house, except when we’re asleep, and she’s incredibly social at this point.
So I definitely say just let your bunny get comfortable with you and realize you’re not a threat. Treats and sitting on the floor and letting her approach you seem to work really well. Good luck with your new bunny!! 