Unfortunately, if I don't have any caffeine more towards night, I'll likely be in withdrawal early the next morning (I also work second shift, and wake up right before work, roughly 1 PM, and go to bed around 3 AM). I'm waaaaaay too addicted to caffeine, and every time I try to wean off of it, the addiction comes back with a vengeance. As for the screen time, you can try blue light filtering programs for your computer like f.lux that slowly adjusts your monitor to steadily reduce blue light based around your timezone and when you set your wake up time.