How Can Constant Headaches Be Treated?
Ibuprofen is more effective
Detailed Answer:
I read your question carefully and I understand your concern.
You mention to have taken lemsips which contains nasal decongestants, am I to understand that you also have nasal congestion and discharge? Any other symptoms apart from headache? Also is it the first time you have had such headaches, any prior medical problems.
Judging from your description I would say that one cause to be considered would be sinusitis. If you have nasal congestion it would be even more likely.
The other most likely possibility would be that of tension type headache, the most common type of primary headaches (primary meaning without an identifiable cause), often triggered by stress and anxiety. Headaches can persist for up to a week
Paracetamol you have been taking is not enough for either tension type or sinus headache. Ibuprofen is more effective, in dosage of 400-600 mg, up to 1200mg/day. If the headaches persist for the next couple of days despite Ibuprofen I would get checked by your doctor for possibility of sinusitis which if confirmed by tests might need antibiotics.
I remain at your disposal for other questions.