Meth was injected into my left arm to the right of my elbow a week ago it stung a little I did not feel it so I am sure it was a miss my whole forearm got swollen and hurt it looked bruised now it is a golf ball sized red lump it hurts to extent. My arm when I touch it and some time just. Quick spurts of pain how long is it going to be before it goes away is there any thing I can do to make it go away faster should I go to a doctor?