DS wont fall asleep

My son is 14 weeks tomorrow. He has been fighting tooth and nail every.night. for a while now. He used to have no problems at all.

He thrashes his head back and forth and spits the pacifier out. He'll be super asleep, spit it out and immediately start crying inconsolably until I just hold it in there until he falls asleep again. So he spits it out again and repeat. For a few hours. Every night. We always give us and feed/rock him in there somewhere.

Tonight I'm trying white noise on a laptop. We did jammies, and played a little, had some food, and now he's in the crib. We've been playing 'spit the paci out but fall asleep kind of' for about an hour..

I dont know when to let him cry or for how long.