A. It sounds like you are describing a common condition called torticollis, in which a newborn has limited motion on one side of his neck. This can lead to his always looking in one direction with a tilted head and getting a flattened head because he is always lying in the same position.
Fortunately, congenital torticollis can usually be treated with gentle stretching exercises. A physical therapist may be able to help you do this if you are not having much success on your own.
Occasionally, if physical therapy and exercises are unsuccessful, surgery is sometimes required to release the tight sternocleidomastoid muscle in the neck.
Since he is only five months old and you don't mention having worked with a physical therapist, you might ask your Pediatrician or the Pediatric Surgeon if that might be an option for you before you go ahead with surgery.
Treatment, even with physical therapy, or a combination of physical therapy and then surgery, is important though, because otherwise your child may always have limited motion of his neck.