What to do if i was diagnosed with bronchitis, i finished my antibiotic and i'm still very sick?

Go back to Dr.: It may be possible that your bronchitis is due to a virus which would make the antibiotics useless. Viral infections usually resolve on their own after 1-2 weeks if you are generally healthy. It may also be possible that the antibiotics you were given were not effective against the bacteria. Either way you should go back and see your dr.