Only if you took it right after contracting lyme. Once it's been in your body for a while, Antibiotics don't work for most people. They will suppress the lyme while you're on them, but once you're off, the lyme revives, so to speak. Doxy won't get into the places where the lyme is embedded in enough concentration, and the lyme can take a temporary form which resists the antibiotic. Once you're off doxy, it's party time for the lyme.
I would think having been on doxy for a year would really take a toll, and would have caused some severe candida. My guess would be that this in itself could drain the adrenals.