CRPSbe,
I am so sorry you're having to deal with the additional worry of Lyme. That would be concerning to any one of us.
Here is an article from Medscape, updated June 29, 2017, on which antibiotics to use for Lyme, at what dose and for how long. The shortest duration appears to be 14 days and can go quite a bit longer. I am close to medical staff and haven't heard talk of shorter courses for what it's worth.
Lyme Disease Treatment & Management: Approach Considerations, Treatment of Early Lyme Disease, Lyme Arthritis
I hope you feel better soon and have a full recovery