Hi, welcome to the forum, the important causes needed to be ruled out are Deviated nasal septum (DNS) and allergic rhinitis. These conditions can lead to sinus infection, ear infection and headaches.
Other possibilities are laryngeal web, asthma, any structural abnormalities in the nasal passage such as nasal polyps, hypertrophied turbinates etc.
Recurrent infection is sign of low immunity. You need to increase immunity by proper nutritious food, regular exercise, mental fitness etc. Vitamins, minerals, proteins will boost your immunity.
You need to undergo detailed examination of nose and radiography of the sinuses to rule out existing sinusitis.
The septoplasty or rhinoplasty for deviated nasal septum (DNS) will help you to relieve your symptoms. Oral anti-histaminics and nasal corticosteroid spray against prescription may help to alleviate allergic rhinitis symptoms. I suggest you to consult an ENT specialist. Take care and regards.
I think you should consult with your dr. Many people mistake allergies for a cold. I would suspect that your allergies are more severe than you think.
Another option would be acid reflux which can cause sinus and asthma symptoms.
You need to see a dr for an accurate diagnosis and then work from there.
Treatments I would recommend would include: sinus rinse with a NielMed bottle (you could use a neti pot but the bottle is more effective - most effective part of my allergy routine), antihistamine like Zyrtec or Allegra (generics would be fine), then prescription meds like a nasal steroid or antihistamine. You could try OTC GERD meds as well like Zantec, Prilosec, or Zegrid.
See a dr so that you know exactly what to treat and feel better.