Is this normal? Tell me no!

So, my Harrison, my lovely, easy, sleeps anytime he's horizontal 18 m/o has stopped napping. Just up and stopped. About 6 weeks ago he was cutting all four molars (or whatever those big ones are) and I think that's where the trouble started. But he's gone from two long naps a day to ... nothing. I want to try having him nap with his brother instead of in his PNP in our bathroom, but he will literally scream bloody murder for sometimes 25 minutes, then wake up screaming, or he will scream for over an hour. Why??? Is it possible to go from two long naps to no naps at all? I know he's tired, as he'll fall asleep in the car at nap time. What is going on?

more attempts at a picture

hey Santa, help a kid out!