It also sounds like he has sensory issues. Sensory integration disorder is when the brain processes input from the senses in a different way. Your senses are either way too sensitive or not sensitive enough. I always called myself a texture person. Many textures of things drive me crazy. Anything itchy drives me up the wall. My mom and brother are the same way. I am blessed in that my mother is absolutely gifted as a seamstress and clothing designer and she made my clothing as a child so nothing ever itched. I probably would have refused to wear clothing ever if it had. As a small child I apparently stripped off any and every article of clothing that they put on if it bothered me. It didn't matter where we were. This was the early 1970's and I embarrassed my mother fairly often with this. Or so I am told. I don't remember.
So it could be worse.
I am also the pickiest eater you can imagine. I don't eat it. You name it, I likely don't eat it. Especially vegetables. My father is the same. Mostly it is the texture of them. Sadly it has gotten worse as I have gotten older.
There IS help!!! It is called Occupational Therapy. One type of therapy is called brushing therapy. The Occupational Therapist (OT) will teach you how to do it at home, and it is combined with gentle joint compressions. most kids like it, or at least don't complain. It is known to rewire the brain without any medication at all. It really helps. My youngest has serious Sensory Integration Disorder (SID) (sensory integration disorder). He would get so overstimulated at school that he couldn't attend ever day. He would shake and shake like he was vibrating and he would literally shut down mentally and emotionally if he went every day. So in preK he went 2-3 days a week, and we played it by ear to the point that by 3nd grade we were so excited that he only missed 1/5 of the school year. That is only 1 day a week. It was a HUGE improvement for him. Brushing therapy was the key to this.
To learn more about this, read The Out of Sync Child by Kranowitz. To find activities to help with therapy for sensory integration disorder, read The Out of Sync Child Has Fun by Kranowitz. The library should have both, and if you are going to buy one, buy the Has Fun book. We wore out at least 2 copies because the activities are truly fun. You will know which activities will help your child because he will enjoy them. The ones he is drawn to are the ones that will help him. Every therapist we worked with told us this. When we brought the book out, every kid in the neighborhood would end up in our yard to see what we were doing and to join in. It truly was full of fun things to do, and ideas to make it cheaper to do them.
I am sorry your little boy is having problems, but I hope that you can help him and can find ways to have fun while you do it.
One fun thing that many kids enjoy - fill a 1 liter soda bottle with rice and small buttons and other objects. Leave a little room so it shakes and the small objects can be hidden and uncovered. Seal the lid with silicone seal (like for sealing windows) so it doesn't come open and spill everywhere. Keep it in the car or a bag to take to waiting rooms. It is great to start stories, or to keep kids busy when you are on car trips, etc......