Smoking and its problems

Hello, I'm 18 years old, I smoked 4-5 cigarettes a day for 4 years, I had surgery to remove my tonsils, I now have one problem, phlegm... I wake up with phlegm, I go out for a walk, I have phlegm... I don't know if it's from the tonsils or from smoking. If any doctors are reading this, please advise something. Thank you)))