2 month old cries and doesnt sleep much

My 2 month old wpnt stay still and cries alot. Also he won't sleep. He's been seen by the doctor but there's nothing wrong. I feel so stressed due to not knowing how else to calm him down. I feel like a horrible mom. I've never had this much problems with my girls when they were babies. My poor little man cries and it hurts to not be able to help him.