Any mom's have experience with Sensory Processing Disorder??

My 5 year old son was diagnosed with sensory processing disorder last year. Since, then he started Occupational Therapy, but our insurance decided to stop paying for it. The place he received therapy said that the reason the doctor listed for the therapy was not good enough. We are in the process of getting the necessary evaluations.

Anyways. He was placed back in head start instead of pre K, because that's what his therapist recommended. His class has had 3 different teachers this year, which I know is bothering him. I cannot seem to get him to want to stay at school now. He looks so uncomfortable and miserable. I cannot get him to maintain eye contact with me, which makes practicing letters and things of that nature almost impossible. We took him to the circus and he plugged his ears the entire time. I feel awful, because I literally have no clue how to help him. Please, if you have any advice let me know. I feel so helpless.