I missed a shot of meth in my left arm&one in my right arm the next day(yesterday)&both my arms are swollen red&hurt(badly) i'm no longer use(my decision) inject site in crease of arm affected area about 10" diameter. how serious? started amoxicillin?

An MD should examine & advise you. I agree with the use of antibiotics for presumed cellulitis but amoxicillin wouldn't be my first choice. Cellulitis, a serious bacterial skin infection, requires an accurate diagnosis, proper treatment and follow-up care.

As bad as the infection is, using meth is far worse. It is destroying your brain. Quit using it while you are ahead.