As a PP said, nothing works perfectly for every child. I would also add that nothing works perfectly for every FAMILY including you, SO, and ODD. And what works for you will change over time.
I agree that 5 wks is too young to be doing controlled checks or whatever they are referred to. I DO think that you coukd start introducing DD to falling asleep in the swing or bouncy seat? Happiest Baby on the Block was very useful for me to realize that the transition from snuggling in mama's belly, to smuggling on mama's chest, to laying on a cold, totally still surface all by myself, would be difficult - and some kids ARE harder than others.
Elizabeth Pantley's No-Cry Sleep Solution is also helpful in encouraging good sleep habits... Not a cio approach at all but rather starting from wherever you are, and getting it to work better.
And i wouldnt worry about daycare- those ladies are magical :-). My DD was the same way. She did not nap unless held til 9 mos but would lay down AWAKE in her crib and nap at daycare!
Hugs mama! I know the sleep deprivation is tough - take care of yourself too!