I'm not sure this is a violation of HIPAA laws. If they told your parents without the waiver, that's a violation. Reguiring you to sign the waiver, however, I think is well within the law.

Yes, it's a little coercive, but not illegal.

You don't have to sign it.

I also think they have to right to discontinue your treatment if you don't sign the waiver. Also well within the law in some states and depends on what that particular agency's procedures are.

It may be time to find another place.