Someone shot me up with meth three days ago for the first time ever last night that spot started hurting and is red swollen hot i refuse to go to the er i have family who works there i have amoxicillin 875 mg twice a day for ten days will that help?

At the very least, you have an injection site reaction, but more likely this is a local abscess that possibly could emerge into a cellulitis or more. It is impossible for us to assess the potential organism(s) and whether there would be sensitivity to Amoxicillin. Contact your regular doctor, but also consider contacting a Drug Crisis Center as an alternative option.