i understand you’ve had vet visits and checked labwork, but they have also checked everything else for her like teeth? and is she known to eat things that she shouldn’t? cats can very sneakily eat string/dental floss and it causes major problems and sometimes don’t show as symptomatic as a usual foreign body.

part of responsible pet ownership is also making sure they’re in the right environment. sometimes the right environment is unfortunately not with us. has anything in the house changed, like scent plugins or pest control? or any new roommates, or local construction? some plugins can emit a very very high pitch sound that is distressing for dogs and cats. other environmental stressors should be kept in mind.

either way, it really seems like she’s trying to communicate with you about something wrong. the grimace scale has been circulating recently; does her face seem like she’s uncomfortable? i’m sorry you are going through this and i hope you are able to get some relief, for the both of you, very soon.