If a professional is required by law to make these reports, and makes you aware of these duties at the start of your care, then there is no valid ethics complaint and no violation of trust. The therapist must tell you in their informed consent about these limits to confidentiality and should have done so before any personal information was disclosed to them.

While there is a potential of some harm due to this disclosure, therapists are not in a position to investigate and determine if abuse / credible threats of violence occurred and are explicitly not supposed to do so. They are supposed to make a report and allow other state agencies to investigate. If OPs family ended up hurting someone and the therapist was drawn into legal proceedings, they could equally be sued for having this information and not following their duty to warn.

OP, these issues do belong in therapy and you should be able to get support for them.