Suggest Remedy For Painful And Swollen Knot On Lip Due To Biting

i bit my lip over a month ago and it was pretty bad.it had a knot where i bit it and i thought it was fine more or less,i kinda forgot about it and just lived with the "knot" that was there after it healed.well today its starts to hurt it the spot where the "knot" is so i go and look in the mirror and its black and its swollen back up,should i be worried about it or just wait and see if it goes away?