Hi,
You have multiple problems like headache,
neck pain, burping and feeling phlegm.
All these symptoms put in together can be due to viral infection.
I would advise you the following in such a situation:
Take an anti-inflammatory medicine with painkiller properties like
Ibuprofen.
Steam inhalation and gargling with warm water to loosen the phlegm, try to expectorate well.
Decongestant medications.
If you develop
fever of if the phlegm is yellow or green then you will need a prescription based antibiotic from your Doctor who will also examine you and order for any relevant investigations before adding any other medicines.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. T. Chandrakant, General Surgeon