How to expel mucus from the chest?

i am 23 yr college student having chronic allergic from 6 years. Every day my nose produces tonnes of mucus of which some are blown outside some had accidentally slipped inside (in my chest). i have tried expectorants like ambroxol but it didnt work i am also practising chi gong (chinese pranayama) and neti pot from six months which helped me alot but it doenst expels the mucus n this mucus thing inside me is still a worry can somebody helpppppppp????