I Am An IV Meth User Of 5 Years. I

I am an IV meth user of 5 years. I have missed shots before but this time I shot up .25-.40 grams of crystal meth into my top wrist vein. There was pain, redness, swelling and numbness for the first week. As to be expected. However now, over 3 weeks later, it is a rock hard lump the size of a grape. What has happened? What can I expect and how long will this stay?