Sir i consulted for second opinion and now the other ent doctor has asked me not to opt for surgery insted he prescribed me with medicines for 45 days?

Reasonable: Treatment with antibiotics is the standard first-line treatment for patients with sinusitis. Amox-clav or Augmentin (amoxicillin and clavulanate) (what you were given) for 2-3 weeks is an ideal first option. Other possible medications could be oral steroids, with allergy medication/sprays as and adjunct. Surgery is reserved for recalcitrant disease that does not reposed to multiple antibiotic courses. Follow up is needed.