I Missed While Injecting Meth. It's Very Swollen Hot And

I missed while injecting meth. it's very swollen hot and red it's only been a day but. ow it feels like all the blood is rushing threw my arm to fingures it's throbbing I am putting heating pad on it now it feels good when that's on what should I do , I also have another one on same arm but it's like a knot now not painful