Glad to see I'm not the only one using the "Caffeine nap." I was lucky enough to work in a place that actually had a dedicated nap room that I utilized regularly. It was a holdover from the old astronomy days when astronomers would spend long hours on site to complete their research.
Do you have AD(H)D? Caffeine-induced sleepiness (or non-stimulation) is a pretty distinctive sign of that. If so, I'd discount all caffeine-related tips from people who don't.
But in any event: if the coffee has affected you, you're already too late. The idea is to sleep immediately after consuming your caffeine, then wake up as/before it starts to affect you. If caffeine makes you sleepy instead of wakeful, that's probably going to be less pleasant because you won't wake up refreshed.
Finally: I suspect the sleep is helping but feeling useless. Adenosine is one chemical that makes you feel sleepy, and levels are reduced while you sleep. But caffeine is an adenosine blocker, so it's going to stop you feeling that adenosine sleepiness without disposing of it. Good sleep while caffeinated is probably hard to get, but if you succeeded I expect you would lower adenosine levels, but not feel the difference until the caffeine wore off.
I prefer to pretend that I don't have anything to diagnose, it's some "irrational personality" quirkiness, but yeah, my attention span is extremely short, 10 minutes on the single task, which is kinda a problem in programming world. Maybe.
I don't feel sleepiness every time I drink coffee, it's highly correlated with how tired I am, but I feel changes in my body and mood almost before I finish the cup. I didn't realize that some people can get a nap before caffeine kicks in before that post.
