Thanks for the query.
I would say there is no substitute for breast milk. The advantages of breast feeding is numerous. If possible, take leave for 2-3 days and just be with your baby. The mother's touch ,warmth and breast milk might be all that the baby needs to feel better.
Since your baby is 5 and a half months old, you could introduce other foods like rice gruel( kanji), pressure cook the rice in a lot of water , add a pinch of salt and give it as a porridge or dilute it with water and blend it. Coconut water is also very ideal, continue giving that. Main thing is we want to prevent dehydration
. Dehydration can be prevented by rehydrating the baby with breast milk, coconut water and rice gruel. Not all cases of loose stools need antibiotics. I feel after you consult with your physician , you can probably discontinue walamycin
Hope I have answered your question. I will be happy to answer any further queries you might have.
Have a nice day,