Hi P.,
When my DD was a newborn, she was like a light switch--one minute she was content and happy, the next minute she was starving. If it took as long as a minute or 2 to get ready to feed her, she was screaming. I learned to start nursing her before she actually acted hungry or she would gulp and gobble and have gas. She too seemed to be wrestling to swallow as if she couldnt drink fast enough to satisfy her. I would talk to your baby soothingly and tell him you were getting ready to feed him and handle him gently, unhurried. Perhaps once he realizes he is hungry he gets more riled and is acting starved thus the wrestling. If you have him on a schedule, perhaps feeding him 10 or 15 mins earlier will avoid his frantic drinking. HTH