Why do I KEEP FALLING ASLEEP

I am seriously at the end of my fucking rope. I know that as a kid, I had trouble sleeping and generally didn't need much sleep. In middle school, I never fell asleep in class even though I started to sleep more or stay up later. In high school, I'll admit my sleep schedule wasn't the best, so I would maybe fall asleep in the late morning before lunch, but not extensively in a way that seriously disrupted my academics (only one teacher ever commented on it). Enter college. All of a sudden, I'm just EXHAUSTED all the fucking time???? I can fall asleep anywhere and anytime, no matter how much I slept the night before or if I've had caffeine or not. I thought it would get better after my mental health started improving and I worked on my sleep schedule and I adjusted, but it has gotten worse. I fall asleep almost GUARANTEED every fucking lecture or when I do readings!!! About 20 minutes into anything, I get hit with a wave of sleepiness I cannot combat. I've tried caffeine, no caffeine, sleep, no sleep, ice cold drinks, gum, literally hitting myself. Nothing works. Not only is it intensely embarrassing, I'm then having to spend even more time making up the material from lectures outside of class, which with my executive dysfunction is a fucking nightmare. I have days where I genuinely cannot stay awake and basically sleep all day. So I took advice and did a sleep study (both night and daytime ones). Results?? Fucking NOTHING. I don't have sleep apnea. I don't have narcolepsy. None of my meds (I'm on birth control, allergy meds, and duloxetine 60mg for anxiety/depression) have this as a side effect. I really thought maybe I would find a solution to this before I finished college, but here I am, graduating in 2 weeks, with no solution. I love learning. I love my major. I love reading. This is actually so fucking devastating. I've read about maybe intrusive sleep from ADHD (which I only got diagnosed with like... 1.5 years ago), but even that doesn't seem to have a solution. Please, if ANYONE relates or has a solution that worked for you, just help me feel less alone and insane. I feel like I'm making it up or that I am just not doing enough to fight it.