It's been four days now since I noticed that my gums hurt, particularly on the area where the gum and tooth meet. The gums do not bleed and are not swollen. I think it might be an exposed or damaged nerve but I am not sure though and I am desperately hoping that this is not the case. They hurt so bad when a pressure is applied to them like when I touch them with my tongue or finger. Can anyone tell me what this is? How can I heal it? I am broke for now so I cannot afford to go to the dentist yet.
Please help! Thank you in advance.

Upload image