I am sorry to hear this, it must be disapointing. Please remember you are not defined by this one test! You are still the smart kid you were before you got this news.
With this score, yes, all the “elite”/famous boarding schools are out. If you want to go to boarding school no matter what, you could look into Salisbury and Trinity Pawling. Last I knew Salisbury had rolling admissions.
Or, stay at your local public school and work on getting straight A’s and see where you are in 3 years. Good luck!