Hi, I'm having sore tongue for almost 3 months...

Symptomes and treatment of chronic Aphthous ulcers 
Aphthous ulcers are a common tongue ulcers that cause sore tongue, its mainly caused by immunologic reaction for an unknown reason, sometimes its associated with other rheumatological, immune diseases. Ulcer it self can got infected with bacteria and overlying fungi to produce white plaques that can be rubbed off the rongue in addition to painful swelling of neck lymphnodes, its treated using Miconazol 2% oral gel twice daily in addition to prednisilon 5 mg tab twice a day for 5 days, to releive pain you can use Lidocain gel twice daily. If the white lesions cannot be rubbed off its called leukoplakia which can be a pre-malignant condition associated with painless enlargement of neck lymphnodes, you are adviced to consult a gastro-entrologist for further investigations. Ulcers are not a side effect of sulfasalazine  
Investigations 
After proper physical exam you should do cbc to detect infection, B 12 level to uncover B12 deficency, neck Ultrasound to look for lymphnodes swelling, Biopsy from the lesion could be taken to examine the tissue for any signs of malignancy 
Causes 

• Aphthous ulcers 
• Fungal infection 
• Leukoplakia 
• Squamus cell carcinoma 
• Crohns disease 

Our advice 
You are adviced to have a well balanced diet rich in minerals and vitamins from its natural sources of fruites and vegetables, avoid smoking and have regular exercise