With a sore throat for months; following should be considered for your symptoms;
1) Epstein Barr virus (EBV)-associated mononucleosis
2) Parapharyngeal space infections,
3) Peritonsillar abscess ("quinsy"), and
4) Submandibular space infection
Following investigations, should be done (your primary care physician can perform them, though ENT specialist would be ideal);
1) Throat cultures have been the "gold standard" for diagnosing GAS (group A streptococcus) pharyngitis and another pathogen, such as N. gonorrhoeae.
2) Blood counts
3) EBV virus antibodies
4) Indirect laryngoscopy (ENT specialist see the inside of the throat by a mirror).
5) Lateral (side neck)) cervical view of the plain radiograph, exposed for soft tissue detail.
6) Blood work for diabetes.
If the throat culture is positive and counts show the infection, injectable antibiotics would be needed. Antibiotics of choice are;
1) Penicillin G plus metronidazole
Please feel free for your follow up questions.