You have been smoking
for seven long years. Your current breathing difficulty can be due to a lung infection
, if you also have fever
. If there is no fever and cough, then it may be due to the gradual change that occurs in airways due to constant exposure to smoke. There is no need to worry. Consult a doctor who will advise you regarding the medications you should take. Meanwhile consider quitting smoking. If you quit now, much of the damage that has occurred, can be reversed.