Hey So I've Been An Iv Meth User For Several

Hey so I've been an iv meth user for several years. Recently I have noticed some odd things happening! For 4 days now when I do a shot i will get swelling in places I've shot up in the past. Im confused normally if I get swelling it's where I missed and gets swollen immediately but now even when I don't miss I randomly get large lumps that are fairly hard somewhere else on the same extremity!