Nightmare napper

My LO is 3.5 months and a terrible napper. I try putting him down fully asleep, sort of drowsy, and awake, but nap time is always a fight with lots of crying the involves multiple attempts to lay him down in his crib. When I get him down finally, he only stays asleep for thirty minutes. If I let him sleep on me, he can sleep for 1-1.5 hours. He ends up super cranky and overtired by the end of the day. I've been tracking his sleep and he's only getting 11-13 hours of sleep per day when babies his age should get 15-16 hours. I've tried darkening the room, white noise, three different swaddles, no swaddle, but nothing is helping. He also hates the rock n play.

Any advice on how to get him to nap more easily and stay asleep longer?