What Should I Do For A Hard, Swollen, And Painful Lump Under My Skin After Injecting Methamphetamine?

Hi, I’ve shot meth before and missed and also have been right on point with it, but I’d say 2 days ago or i shot into into in inner arm corner by the elbow, usually if I do miss it stings and burns but it goes away with heat and ice, this time though it feels like there’s a hard ball under my skin. It hurts to even extend my arm. And it’s definitely swollen and red. What do I do?