When I have a rough day or don’t sleep well the night before, I take a 30 minute ‘nap’ when I get home after work. It’s strictly 30 minutes.
It doesn’t matter if I fall asleep or not, it’s a strict 30 minute limit. I set a timer and I stand up when it rings. This lets me turn an otherwise completely wasted evening into something salvageable. Then, I can have a regularly active evening - I cook, play games, paint, whatever.
I don’t really have trouble falling asleep after that at the regular time, or maybe an hour late. I do struggle sometimes to ‘boot up’ after the nap, and it doesn’t always help (mostly when I don’t actually fall asleep) but it has worked for me more times than not.
Also, I drink a LOT of coffee - way too much. This is what works for me.