I Am An IV Drug User. Yesterday, My Left Leg

I am an IV drug user. Yesterday, my left leg started itching and I noticed something like hives coming up everywhere on my leg. I had had a migraine the night before and taken Ibuprofin but when I woke up it was still lingering. So when the hives/rash showed up I took Excedrin Migraine and Benadryl. The headache never truly went away, and it started to feel more like congestion. And all night last night I ran a high fever. My leg is still red and swollen and hot to the touch in patches and I still feel a bit feverish. My worries were that I may have shot up water that had some sort of bacteria in it. Should I be worried at this point???