We have a Rattie too... and sometimes she does just get a Rattitude problem!

Our Holly is very sensitive to different things. She will suddenly decide the TV is too loud for her, and choose to go to her bed whenever we watch TV. This will last for a few days, and then she is goes back to normal sitting with us on the couch. She will also do this (go to her bed) if she doesn't feel quite herself, rather than wanting extra attention, like I would think she would want if she wasn't feeling well.

It might also be an adjustment to being back home after being on vacation? Her everyday "normal" life was changed being on vacation... and if she still isn't feeling completely well she might just be feeling uneasy. Maybe another vet check would be a good idea to make sure she doesn't need another round of med if she doesn't perk up soon?