Oh what a frustrating and dangerous situation you are facing. You speak of skinned knees and black eyes - you could face even more injuries if it continues.
There are practices that are known as "Dizzy & Balance Centers" that work on diagnosing the reasons for dizziness and falling that have not been found in your normal care. The staff can include ENTs, neurologists, and Physical and Occupational Therapists. Perhaps you can find one in your area. They are often part of large multi-specialty practices.
For example, Mayo Clinic offers such care: https://www.mayoclinic.org/diseases-conditions/balance-problems/care-at-mayo-clinic/mac-20350479
Sue