Seems like an ameloblastic lesion, Get biopsy done Immediately, consult oral surgeon and oral pathologist. Pain in such lesions seldom occur.

Your OPG show that you have an impacted tooth in the lower left jaw inside the bone. This tooth has given rise to some pathology which is clearly seen in the radiograph. It is probably a cyst. Go to a maxillofacial surgeon to treat it. You can see this from the black spot in the jaw. This means that instead of the solid bone, that are is filled with fluid. As such, the strength of the jaw is reduced.

hello you have a very large cyst in your lower jaw which needs immediate attention. Kindly go to your nearest hospital as soon as possible. If avoided it can lead to fracture of the jaw. Thank you