Bad sore throat 3 weeks...fever on/off whole time..strep/mono both negative...can't swallow..reg dr not helping much..what else could this be..30/f?

Sore throat: Other possibilities include Hemophilus influenza, which is a common bacteria; virus; abscess in tonsil or pharynx; I recommend another check

Allergies or...: Postnasal drip. It could be that you have allergic rhinitis or drainage that is dripping down the back of your throat. If you have a real fever (100.4 or greater), it probably isn't allergies but still could be drainage from sinusitis or rhinosinusitis. Also, coughing and garden variety viruses can make a person have a bad sore throat

Sore throat: Given how long it's been going on, an empiric course of antibiotics should be tried. We don't know anything about your health or social history. If you. Are healthy, non-smoker with no allergy or reflux symptoms then it's most likely an infection. Gargle with salt water for relief, it may be a tonsil stone. Hydrate well and may need to see ENT for exam. Lingual tonsillitis or epiglottitis possible