Stressed cat?

Hello there , so I recently adopted a cat and took her to the vet. for time today , the vet was quite far so we took quite a long car ride , she was meowing throughout the entire ride , and at some point started panting with her mouth open. Now that we got home she went to sleep but her breathing rate is really fast and she refuses food , she still comes near me and doesn't seem skittish.

Idk if this will resolve eventually , please if there is any advice I'd be thankful.