You have already consult your doctor and treatment is going on, so no need to worry.
As far vomiting
, may be it is medicine indues, If your son vomit soon after taking medicine, you can repeat the medicine after some interval.
I would advice:
1. Avoid exposure to cold
(cold make ciliary activity sluggish and hence the organisms tracking
down the airways cannot be swept out, making a progression to lower respiratory infection)
2. Keep your child warm (Wrapping with cotton cloth )
3. Stem inhalation with precaution.(Plain water do not add any decongestant like vicks
4. Try to increase his immune system with proper and regular diet.
5. Maintain hygiene.
6. Don’t use more medicine
7. There are some baby chest rubs that can be used to help relieve nasal congestion
8. If she is not recover within 5 to 6 days you can consult again to your doctor.
I wish your baby recover soon.
Regards , Dr. Sagar Mhatre