Since ventolin helps you, it is probably mild
asthma. Ventolin tends to only work for 4-6 hours and less if there is a lot
of inflammation in your lungs.
Defintely worth a doctor visit for full pulmonary tests and possible methacholine challenge to prove or disprove the asthma diagnosis.
Since you do smoke it is also possible to have COPD or possible lung cancer so you need to stop smoking and get your butt to the docs.
Let us know how it goes and if you have any other questions.