If your panic attacks are less intense and you feel like you have a connection with her, then it might be worth it to stick things out with her.

You can keep asking her why she is focusing on your schizophrenia than on your trauma.

If she's working with you on the issues that you're facing, it won't matter so much what the diagnosis is.

Just thought I'd through this out there... but if she thinks that you have paranoid schizophrenia, then hypervigilance may just be a part of that, and it may be why she is focusing on this.

Hypervigilance

That site mentions how hypervigilance can be found in paranoid schizophrenia. Perhaps she feels that it is a more fitting diagnosis for you than PTSD, as C-PTSD isn't in the DSM and she may want you to be able to pay for things with insurance and whatnot.