A notice of termination from the landlord is not the same as an eviction. Section 8 program rules are quite different than the regular landlord/tenant codes. If you receive a notice from the landlord, you are wise to comply. Do not take a chance with losing your voucher.
Seek the advice of a local legal aid agency. If you receive section 8 housing assistance, you will automatically qualify for their free legal services. If the agency tries to charge you, then it is a sham agency. Legal aid can also guide you toward appropriate testing and/or counseling for your son. I do not know how old he is, but his actions indicate a special needs issue.