3 month old sleep

I’m just going to assume this has been asked a million times but I’m sleep deprived and desperate. I have a 3 m/o that takes about 3 hours of holding and shushing before falling asleep each night. The issue is that the second his body touches the crib he starts flailing both arms and legs and starts crying which starts the whole rocking and shushing again until he falls asleep. I need some tips. I’m tired of reading the same 5 BS articles over and over that tell me what I already now. Yes I know he’s just a baby, yes I know the cold tundra of the crib is different than my warm arms and yes I know he should not be fully asleep when put down. Nothing works. Just need some real world advice. TIA via /r/Parenting https://ift.tt/2MEOGLI