Hi, totally get your panic because of what we hear on the news about MRSA and Staph but I will try to reassure you a little!
You are right Staphylococcus is sometimes present on our skin, its an opportunistic bacteria so basically as soon as the conditions are right (wound, moisture etc) it will grow and multiply. I actually worked in a lab on MRSA so it's likely I've got it in my nasal passages as part of my microbiome
If you don't mind me asking are you immunocompromised in any way? If you aren't hopefully with the help of the antibiotics your body should clear the infection up soon. I dont think the doctor would have prescribed them if they didn't think would work as they've got really strict with antibiotics because of the widespread resistance that's occurring! Obviously if you don't notice a difference in a few days definitely go back
If you don't mind me asking are you immunocompromised in any way? If you aren't hopefully with the help of the antibiotics your body should clear the infection up soon. I dont think the doctor would have prescribed them if they didn't think would work as they've got really strict with antibiotics because of the widespread resistance that's occurring! Obviously if you don't notice a difference in a few days definitely go back