Hello. Hope you are doing well. The cause of your concerns can be several including caries, gingivitis, temporomandibular joint disorders, abnormal oral habits, etc. The OPG provided shows attrition of your lower front teeth which might be due to any abnormal oral habits like clenching of teeth in sleep (bruxism), tobacco or betel nut chewing habits, etc. Also, the pain can be due to temporomandibular joint disorders or even myofacial pain dysfunction syndrome (MPDS- causing soreness of muscles of chewing). If it is gingivitis then it can be only diagnosed clinically. To know the actual cause it will be better to consult an Oral and Maxillofacial Surgeon or a General Dentist to rule out other causes.