A persistent cough and a squeezing sound in your throat for a month suggest that the underlying airway inflammation is not fully controlled by your current medications. Since oral antihistamines and cough suppressants have not provided relief, you may benefit from inhaled therapies. A doctor might prescribe an inhaled bronchodilator (such as salbutamol) to quickly open your airways and an inhaled corticosteroid (such as fluticasone) to reduce swelling. Please do not start these without a professional evaluation. I highly recommend consulting a physician or a pulmonologist for a physical examination and a lung function test to get an accurate diagnosis and the safest treatment plan.