Hi jeanninewilber and thanks for your post. While we cannot provide medical advice or diagnostics over the internet (for your own safety), your inquiry certainly warrants a reply. In the most general of terms, over-use or excessive use of antibiotics can render a person to be less responsive to the antibiotic that is being used. The micro-organisms the medication is being used to treat are less susceptible to the effects of the drug. In some cases, it's actually been given a name - MRSA or Methicillin-resistant staphylococcus aureus - would be one example.
I hope this brief answer provides you with the information you are looking for.
All the best,
Leon (site moderator)