For about three years now i have constantly been coughing and hacking uncontrollably cuz there is always mucus or flem stuck in my throat, and it's a lot. what can i do?

You should be examined by your physician and possibly a pulmonologist to determine the cause of your persistent cough and mucus. Only then can appropriate treatment be rendered.

Drink at least two quarts of clear fluids per day. Suck on lemon drops or lozenges. Quit all throat clearing, Swallow instead. No smoking. Limit alcohol intake. Use protective mask if exposed to dust or particulate matter. if you have chronic nasal condition or allergies, see an ENT and/or allergist.