I have felt like I have phlegm in my chest lately (if that's possible), my chest has felt tight lately and I have always coughed a lot, what might this mean?

I think my chest may be irratated from coughing so much also.

See an allergist especially with the comment of "always coughed a lot".

Could be bronchitus. Could be Asthma related. Could be pneumonia. Could be allergy related. Could even be COPD.

The best doc to assess this is probably an allergist. Do it now.