Ive had this cold for 2 weeks now. im tired all the time. when should i go see a doc for what all i can tell is a bad cold?

See the doctor: Sometimes "cold" might indicate other forms of infection like atypical cases of pneumonia Also some patients might develop the same symptoms from getting infection with unusual viruses like that of glandular fever I suggest to see your doctor for opinion

Cold: Colds usually resolve within two weeks. If you are experiencing severe congestion in sinuses, fullness to ears, productive cough or fever at this point, I would recommend seeing a physician. If not, give it a few more days and rest, hydrate and try saline sinus rinses if congested.