Post a clearer picture . With open mouth if any decay in tooth is visible and Another one  Stretch the upper lip even more upward for complete view of the swelling.

I would suggest either visit nearby dental clinic or if not possible at least go for a video consultation. This is difficult to diagnose the case by seeing only this picture. A detailed history to be taken  like for how many days the lesion present over there or any history of trauma is there,you are under any medication or not etc. An xray has to be taken also.