Our DS was exactly the same!!! We went and purchased a gadget that hangs on the cot, or bassinet. It has a dial on it, and you can turn it to make running water sounds, a heartbeat, and a few other natural sounds! It has a dull night light, and you can set it on a timer. DS loved the sounds of water and the heart beating. This settled him instantly, and if he woke, (and didnt need a feed etc of course) we would turn it back on and he would drift off again. It was heaven!!!! We purchased it from a baby place. It is a Philips "Sweet Dreams" Cradle player from Baby Care.
Good luck