Sounds like a possible obstruction- anything missing in the house? Likely when you go to the vet they will want to do an X-ray. Ask them to do it with barium so they can see cloth. Keep going with the canned pumpkin if she will eat it- maybe try to get her to eat bland diet. Use broth or ice cubes to get her to get some fluids. Poor sweet Thelma. You may want to find an emergency vet in your area, she sounds very uncomfortable.