Hey, Anna. Please let us know what you find out at the Vets.
My beloved Rotty, Kilo, would spend most of his days sleeping. When he did move, he whined. Some nights he wouldn't even get up to go to bed. But there were times when he would get energy and play. He would always pay for it later. We used buffered aspirin for him and it would help. He eventually started to get aggressive (not towards us). I guess the pain was too much for him.