troubles with my 5 months old

I'm a first time mom and need help.. my son just turned 5 months. From the day he was born I would rock him to sleep and he would cry when I put him in his bassinet so I end up putting him on my chest for a hour then in bed next to me. It seems that the older he got the more rocking I needed to do and the longer it took got him to fall asleep. I had days when I would rock him for three hours, have him on my chest for one hour then put him down in my bed again. Now 5 months later and he falls aslee after about 30 mins of rocking but I still have to keep him on my chest for an hour before I put him in bed and he will sometimes wake up if I'm not next to him so I end up sleeping when he does. I want to stop all of this... I want him in his crib, I want him to fall asleep quicker and to stay asleep.. plz help me