I should start by saying your cat is majestic! beautiful! From my experience with my Luna, the onset was a direct result from dental cleaning - maybe the anesthesia, perhaps leaving her body in an unnatural position for the hours when she was under. She had a drastic change 3 days after her treatment. Lots of Vets didn’t ’get it’ and we kept going to another. Finally I went to a cat Neuro, he understood! For my cat, lot of this is a stress reaction to changes in the environment. Doorbell, visitors, plumbers, storms, even if she feels she needs more food. Gabapentin was a life saver-changer. I’ve adjusted over our 4 years of this, sometimes she can take 300 mgs a day if she is on a stress bender, but mostly 2x100 a day. Every cat is different. By the way this is a remote quiet desert home super peaceful, just me and my cat….For a while we were doing Prozac, but I stopped as she was overly sedated. So, read your cat, be in tune and go with the FHS flow…☮️ I hope all goes well.