My DS was exactly the same when he was a baby and I found the answer for him! We bought him an Amby baby hammock and were able to bounce him off to sleep in it. He went from only sleeping in my arms to sleeping two hours at a time in his hammock. It was a lifesaver! I think he found comfort in motion, when he would wake up the hammock would rock with his movement and put him back to sleep. It may be worth a try if you get desperate. We bought ours second hand.