Take her to the vet. Any sudden change of personality you can’t explain should be checked out by a vet.
Just tell your vet that your dog isn’t acting like herself. Vets are more trained at noticing signs of discomfort than most people so they might see something you missed.
And honestly anon, I think it’s better to go to the vet and find out there’s nothing wrong than to wait it out and find out you should have gone to the vet.
Good luck – I hope your dog is doing okay! -C