I got blood work done a month ago, all came back negative. my ears feel full and my lower left jaw hurts. and my head kinda hurts. i have no sore throat. no lesions on gum, mouth and tongue. what is this? please help?

Blood work may not be helpful, except for acute mid ear infection. If your MD exam of eardrums is normal, then consider suspicion of jaw joint dysfunction related to your history of jaw pain. Recommend dental evaluation. Temporomandibular jaw dysfunction commonly causes ear symptoms (pain,fullness,pressure) with normal ear/tympanic membrane findings.

Can be from wisdom teeth trying to erupt (You may be teething). See your Dentist or an Oral Surgeon. If that's not the cause, next step is to be examined by an ENT.