D.B.
stop and shop and toysrus sells diaper doublers for 2.99 30 doublers... if it works to keep your son feeling dryer it may be worth it to get better sleep for both of you. I've used them too at night we like them.
But i'm going thru the same thing (almost) my son doesn't necessarily care all day long about the potty then at bedtime he'll drive himself to tears swearing he has to go and wanting to try a few times in a row crying making sure i'll change his diaper, etc
good luck, just know that you're not alone