4 week old doesn't want to nap!

Help me. I am at a loss. My newborn does not want to take naps anymore that are longer than a half hour. I KNOW he is overtired because everything I've read indicates that. But he doesn't want to fall asleep when he is getting tired. I've tried. I've tried to burp him, given him has drops a couple times, fed him some more, rocked him, swaddled, given a paci (which he inevitably spits out)...I feel like I've tried it all. What am I doing wrong??? This is killing me. He used to take a two hour nap without any issue and now that hasn't happened in like a week. I can't take it anymore. Should he be napping in his room or in the dark or something?