Being well-off or raised upper middle class in no way compensates for their atrocious behavior or emotional abuse.

Before you can deal with an escape plan or a bid for independence, seeing a doctor for the anxiety (and possibly other issues such as depression) would be a good place to start. In addition, the doctor can refer you to a therapist; don't limit yourself to one or the other if that can be prevented.

Can you get your dad to pay for medical care? You can tell him you have issues because of your mom, and don't need to point out that he's half the problem at this time. Getting the anxiety under control will be a big help with starting to look out for yourself, first and foremost.

Besides medical things, some self-help is in order as well. A little walking can boost your spirits and get you off the sofa and out of the house, but if you have other interests outside your home, those could get you moving again too. Reading or watching videos to understand the effects of narcissistic or emotional abuse can teach you how and why to distance yourself from attempting to negotiate or reason with them. They're unable to see things from your perspective, and you can't expect to teach them anything, particularly not understanding or empathy.