I loved the book and the audiobook, and I thought how could a movie based on a wonderfully-written book be ever bad? Boy was I wrong. The script, tone, visual adaptation, music, scene, you name it, all bad. I didn't expect it to be a masterpiece like Notting Hill, but its cringeworthiness is on par Ticket to Paradise.
The production team should watch Netflix's Heartstopper and see how proper adaptation is done.