My dog's name is Sammy/ dachsie/ 11years old
She is very lethargic, doesn't eat anything only drinks water.
She pees about 4 times a day, is weak, and her poop is really small
Went to the vet Friday, was sent home w/ some pepcid as she thought it was a stomach ache. Well she is not better by now.

If she is showing no improvement you need to call the vet back, without knowing what was tested for or what was done it is really difficult to advise.
The vet is your best option and a second opinion is not out of the ordinary if you are not satisfied with the way things are going.