First of all, please take some comfort in the fact that you are not alone in this struggle. The CFA Level 1 exam in December 2019 saw a pass percentage of just 42%. Just passing the exam is hard, leave alone acing it.
It’s definitely not because of a lack of effort! Just like you, most candidates try to sincerely go through every single study session and readings, word for word, to absorb as much information as they can. However, this is exactly what leads to their downfall when exam time comes around. They remember a little bit of everything, but never enough of anything
A frustrating failing score after months, days and hours and hours of sincere studying.