I am not 100 percent sure but reading  your symptoms, I feel that trauma few months back may have cause  your tooth to die...... ( Tooth has pulp internally that contains nerves, blood vessels and different types of cells). The dead pulp may have cause some change in the inner end of tooth (periapical area of tooth) so you may be developing gum swelling and tooth may discolor in near future due to dead pulp. If thats the case than the best treatment is to do root canal treatment and save the tooth. I do not think any home remedy or pain medication will be long term or best treatment. If you are in Boston area, than I go to Boston University Dental School. As per the School rules and regulation I can not offer you free treatment but the school rate is very cheap in comparative to any other private dental clinic. Let me know If I can be of any help or please feel free to shoot me an email.

Thanks.
GIG