can't get 9 week old to sleep in crib

Yes I'm guilty I nurse my baby in bed on my boppy pillow and usually fall asleep all night like this. Well now I can not get him in his crib without him freaking out. I put him in when he's asleep then he wakes up because of his crazy arms that swing like crazy and nothing can hold them down like those sleep sacks. I just want him off me but we need sleep. Advice? I think he's going through that separation anxiety stage too maybe.