What Is The Remedy For Swollen Sore Arm After Methamphetamine Injected?

I injected methamphetamine (first time ever injecting any substance and without a doubt the last!) about 10 hours ago. A guy did it for me, brand new needle. He commented I have very small veins, just in last 2 hours my arm has swollen up a bit and is mildly sore like on scale of 1 to 10 it s only a 1. Is a little bit red and firm to touch. The swelling is above the injection site and site is a little sore to touch. I am about to start work so cannot rest it but have been massaging gently and applying warm compress. Hospital will b my only option if need to seek medical help as docs r closed or can go docs tomorrow. Should I b worried? Coz I am!