Something is wrong with my baby?

I thought my son was just high needs but now I'm starting to wonder. He is 6 months old and still when he cry's the only thing that calms him down is loud music or the hair dryer.

He is hyperactive and is so highly sensitive to so many foods that I am on a strict chicken, carrots, potatoes and asparagus diet with fruit. Anything else I eat causes him to be in pain and screaming--I exclusively nurse and yes it's easy to say just wean him onto a hypoallergenic formula so I can eat more but he won't take a pacifier let alone a bottle and his reaction to those two things are extreme.

The longest he has slept for has been 4 hours straight and that's only been maybe 4 times. Most of the time I have to nurse him in a rocking chair and that's how I keep him asleep, he will not nurse laying down. He sleeps maybe 30 minutes to an hour at a time and is not on any type of schedule and not for lack of my husband and I not trying total sleep in 24 hours is a good amount just very broken up.

I'm starting to wonder if he has something wrong. He does have acid reflux which he takes medication for and he has severe food sensitivities but I'm wondering if maybe he has sensory integration disorder or mild autism? He is very smart, very alert, responds to people, happy and no developmental delays but what else would cause such extreme behavior.

My husband had to quit his job and it takes us caring for our son around the clock, one person would not be able to care for him on their own. It's hard to describe.