Sensory-the missing puzzle piece?

As I mention back in March we took Thomas to be evaluated by an OT, because the doctor treating him for SM, believes that his disorder stems from some sensory issues.  They had a very tough time evaluating him, because he was shut down and would not participate, so they felt that his limitations were more a result of anxiety than sensory and so they didn't feel that he would benefit from therapy at the time.   I was kind of relieved, as it was one less thing to worry about and one less therapy session to take him to once a week. 

Four months later, and he is still having so many problems that seem to relate to sensory.   He seems so scared of his environment-swings/slides/movement/noises/crowds.  So we reopened the sensory discussion with Dr. E. and went to see an OT who works with children with SM.  Of course this is not covered by insurance, but we've gone this far and I'm not about to give up on him now, so we march on.  Thomas had his 2nd OT eval, (first with the new OT) on Friday, July 11th.  It was in a more inviting atmosphere, the woman's home, but still he refused to participate/engage over the course of 2 hours.  He refused to get off my lap, as his separation anxiety is still at an all time high.  

So many mixed emotions ran through me-frustration, anger for paying all this money to have him refuse to participate, sadness for him because he was once again scared, and then relief, because as I talked with her and she observed him, she could tell he had sensory issues.  She asked me to write up his life story for her, including my pregnancy, when I went home.  Over the next few days, I work very hard to come up with an extremely detailed view of our son's life and as I was writing this, I could see sensory red flags popping up everywhere!  Separate instances of behavior that seemed like nothing came together to create one big picture of all his sensory struggles.  How did I miss this!?!   Thomas is doing well with using his words when comfortable, but he is still really struggling in certain sensory stimulating environments.  I really do feel that OT will help his sensory issues and may be the missing puzzle piece to getting Thomas to really thrive outside the home.  The new OT believes that she can help him in many ways, including implementing a sensory diet and so we are beginning OT with her every week/every other week as our tight budget allows.