I don't think I read the entire book so this is just one snippet. My brain associates this with books like The Curious Incident of the Dog in the Nighttime. Maybe because it dealt with a young male or because it dealt with mental illness/neurodivergence? Probably around the same time period too. Anyway, the woman (mother?) jumps out if a treehouse to see what it felt like. I think maybe her son fell out and died? The author describes her wanting to feel free, or flying. The author compares the suicidal thoughts to sucking on a lemon candy in an extended metaphor.

It's that quote about the lemon candy that I'm really searching for. Thanks for helping!