The only way to know what this is
for sure is to see a doctor. Testing
for anything bacterial will be tricky since you are on antibiotics (did you get a doctor to prescribe those?), but you should get checked anyway. Given that it's a month, and the skin symptoms are still there, it's not likely to be herpes. Since you have chills (indicating a fever), it's not likely to be syphilis.
Get this checked, especially if you are self-diagnosing and treating for staph. Feel better!