Finding a therapist
If you start looking for a therapist for your child or for yourself, I advise you to look for an occupational therapist, physical therapist or speech therapist who has experience with children and has followed additional courses in the field of sensory processing.
You will probably have to ask for this specifically. Such a therapy is characterised by the vast amount of different materials to feel, or touch your child with, and a lot of different types of swings, balls and other moving materials will be used.
In some countries there 're lists available of therapists familair with and trained in sensory processing.