Not eating, trembling, weak and slow wal

My dog's problem started off with vomitting and not being able to walk properly. Then our vet visited and gave her an injection for stomach worms and said that due to her age (15yrs) she is javing neural problems and thus the shaking and standing, walking problems. Depsite his injection she is still not eating anything properly. She is taking minimum amoutn of food, like the last 3-4 days she has almost had one small spoon of cooked rice or at times is having milk. She is still very weak. Not walking properly, not eating and although her vomitting has stopped the other problems still comtinues. Im asking for a second opinion regarding her health here, as she is very car sick and taking her to a Vet may cause more problems for her. Please so reply as soon as possible.