I feel for you

You might’ve seen it already, but the link might be helpful re mold treatment under CA law. Fwiw when I rented, the only time I can remember a landlord coming into my apartment without permission was when a fire sprinkler in the unit above mine burst, and they needed immediate access to prevent damage to my bathroom and property inside. Your lease should spell those terms out (unannounced entry, repair responsibilities).

The lawyers on board here can answer further, but speaking as a longtime renter, I would definitely document her actions and get everything in writing. And no, you’re not nuts, but you may need someone who specializes in landlord-tenant law.

Click here for link at https://www.cdph.ca.gov/Programs/CCDPHP/DEODC/EHLB/IAQ/Pages