Hello Mrs. I know you've had lots of iseful advice, and have probably stopped watching this thread, but I just wanted to say that your little one sounds just like mine did. She's 7 weeks now, and sleeps great. I was at my wits end too, cos DD number 1 was the easiset sleeper ever, and required no effort. Turns out she was a freak of nature, and number 2 is much more the norm! She wouldn't ever sleep during the day and screamed merry hell if I ever put her down. Number 1 was in a (self imposed) routine from day one, and I thought that unless I shoe horned number 2 into a similar routine, she'd be a terrrrrrible sleeper. Nothing worked though, so against my instincts I bought a sling (I always thought they were a bit 'earth mother' and I'm the more 1950's 'routine, routine, routine type!!. I was terrified that she's become dependent on me to sleep if I let her fall off in there, but was desperate!
Turns out I needn;t have worried, she fell asleep in the sling and started having lovely long naps, then after about 3 weeks, she started to settle well in her cot on her own. Turns out she just needed her mum for a bit longer.
Do anything you need to in the first few weeks, but keep trying him in his basket or wherever you eventually want him to sleep. If you keep doing it, one day, it'll all click.
Good luck, you're doing great!!