bite still itchy after 4 months

2 months ago I was sitting outside when I put my hand over a crack in the ground, before i knew it I felt this horribly painful sting on the side of my ring finger. First the sting numbed the whole top half of my finger and I couldn't feel it of about 30 minutes, then I started getting feeling back and the bite started to itch madly! It then blew up the side of my finger with a nickel size bump that hurts as well as itches continuously.
Now months later it still itches about 2 times a week. It seems like its gone forever... not even a mark! But then it just starts itching like MAD! The bump begins to grow again, and around the bite area its very red and it stings. It drives me crazy and it wakes me up at night as well as gets me up in the morning!
I can't stand it! it was 4:00 in the morning when I got up from itching to finally type this out... I just want to know what bit me, and how can I ease this pain?

-Carli