C.W.
Boys can be very hands on learners- perhaps your sons learning style isn't being met? Which will be hard to find, even with and IEP because public school isn't set up for it. I have many friends who use Montessouri- they love it because it is very hands on. The childs learning environment comes to life. I would recommend visiting a school and sitting in a classroom so you can observe this style. You can also read about it online. These schools are actually very structured. Sometimes people think if a child isn't sitting in a desk all day long there is no structure. Structure is more of a routine than anything else. I would really recommend visiting the schools around you, see what your options are. Since homeschooling isn't an option, maybe a home tutor (teacher) would be a thought? Ask for referrals from parents, keep in mind that not every child learns at the same pace as others.
My Son has SID- diagnosed at 3 and is doing great now and he is 10. I have been through the whole IEP - private school- venture. It is frustrating and sometimes you can feel all alone. Follow your heart and let it guide you to do what is right for your son.
Hope this helps, C.