What Causes Swelling Of Toe And Pus Oozing Out?

My toe is swallen around the bottom of the fingernail and some puss is leaking out, the nail has not grown out for several months and it's turning yellow. it feels like it's growing backwards into the toe (not on the sides), I've been treating it with lamasil and tea tree oil but there is no improvement. What is wrong and is it possible to get blood poisoning prom this puss that is in the swelling?