Yy to sling and to Ebaying the others. IME people involved with sling groups are lovely *& will often lend them out for you to try. Some groups run a sling 'library'.
IMO the best value ones are the sort you can use for back carries when baby is bigger eg Ergo, Connecta, Manduca. Great for cooking dinner with a fretful baby, or needing them out of your way while you have your hands and front completely unencumbered.
DS1 was like this until 3.5 months. Now 5 week old DS2 is the same - except it has to be me and me only wearing the sling.
The other tip on sleep is to wait till they've been asleep about 15 mins - move their arm and see if it's really, really floppy. Then they're in deep sleep and are less likely to wake as soon as you put them down (though they may wake at the end of that first sleep cycle rather than sleep for longer, which is what DS2 does. He'll sleep for just 20 mins in his baby chair or 2-3 hours in the sling. DS1 was the same.)
We've got a baby bjorn type sling & he hates it . We also bought a bag-type one but then read they'd been recalled due to danger of suffocation so not really doing too well. I looked for a local sling meet but there aren't any & we really can't afford any more sling failures.
Mine did this. Wore her in a sling as much as I could. And just kept gently trying to put her down in same place with same stuff as at night. She eventually got it. Took me about a month, maybe six weeks. Empathise though as it's very tough. Good luck!
Put one of your worn tops in the babies bed so your scent is there. Swaddle? It doesn't hurt a baby to cry briefly either. Remember its their only way of communicating and doesn't always mean they are upset. Sorry if those suggestions are not helpful!
I have an 8 week old baby who refuses to nap if he's not being cuddled. If he drops off to sleep & I put him down he wakes & starts crying within minutes. He's fine at night in his Moses basket though. I also have a toddler so can't cuddle him all the time but find the crying really hard to deal with. Never had this with DS1 so unsure what to do, is it something he's likely to grow out of quickly, or is there anything I can do to get him to nap elsewhere?