I'm really terrible for staying up without any sleep at all, but I did go through a period of mental not-wellbeing when I decided to test my endurance. 16 hours of sleep across 6 nights, didn't eat for 5 days straight of that, went without water for around 36 hours, and then played football. It was just a really bad idea - I was fine, but I reckon that was luck more than anything. If there's a reason you can't take anything, that sucks - try things like ASMR relaxation videos, see if that helps you drift off. If there isn't a medical reason, see your doctor about it.