Chin sick AFTER vet put on probiotic and antibiotic

Hey there. This is my first post. I have an 8mo old chin named Juniper (Juni) and she is usually a bundle of energy with a very healthy appetite. Recently an abcess formed on her chest, naturally she went to the vet to have it looked at. They said it needs to be removed surgically and so an appt was set for the surgery. They gave acidophilus probiotic and batril antibiotic to give to her by syringe for the few days prior to the surgery. Well, after administering those for just one day she stopped eating her hay and pellets, she is lethargic and not pooping. Afraid for her well being, she went back to the vet and they said she looked fine still. They sent home critical care and reglan to get her pooping again. Nothing seems to be perking her back up though.

I am so scared for the baby. I stoped the antibiotic after the first day. Just gave her the critical care with some acidophilus and Regan the next day. She was still not eating or pooping. So today I am only giving her critical care. She is currently out and running around with periods of her retreating and sleeping.

I’ve tried everything but she still really isn’t interested in eating. What can I do? I’m beside myself with the fact that she was behaving fine before the vet. Sure she has an abcess but when the treatment makes her more sick than the condition, is it worth it?