this was me during so many years of school and the biggest reason i take my medication is because it helps me not fall asleep as easily  but before meds what helped for me was movement or any physical activity during lectures i would draw knit or something like that to keep my hands busy i also wouldn’t study for an hour straight instead i’d go for 25 min studying then 5 minutes of physical activity no phone just walk around the house or jump around for a bit also taking a 30-45 minute fastpaced walk right before sitting down to study helped   another thing that helped was eating food that was difficult to eat like something you have to peel to get to maybe some nuts sometimes i peeled grapes