Dear Bogdan, hello Exacerbation of Chronic Obstructive Pulmonary Disease is very distressing. As you had history of smoking, the condition is more problematic. Infection of the lower respiratory tract is common in this condition. This will be treated by taking antibiotic. But please take full course of antibiotic under medical supervision. For breathing problem, taking bronchodilator with the Nebulizer is more effective and safe as compared to oral medication. Consult medical guidance to select nebulizing solution for you after your full examination. Steam inhalation will also help to some extent. Avoid doing heavy exercise until your breathing problem is cured as exercise will increase your respiratory discomfort. Hope this is helpful to you. Thanks.