Many of us find taking a probiotic supplement between doses of abx very helpful. The antibiotics (abx) kill off the "friendlies" in the gut and cause a happier environment for yeast (Candida) overgrowth and/or C. Difficile, thus taking a probiotic supplement (acidophilus, etc.) can help reduce the chances for these opportunistic infections. And some find the probiotics help reduce the unpleasant stomach upsets from the abx, as well (myself included...I really feel it when I forget a dose of probiotics).
Also, make sure you take the Doxy with a substantial snack or full meal to reduce stomach irritation, and stay upright for a while after taking it so it doesn't irritate your esophagus. Some say eating dairy products (milk, cheese, ice cream, etc.) with Doxy makes it less effective (it's ok to eat dairy between abx doses).
You might contact the LLMD's office and ask to speak with the nurse/medical assistant about the dose of Doxy you are on given your petite size.
Chronic Lyme Disease, Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, chronic Lymphopenia, intermittant pancytopenia, chronic malabsorption/malnutrition, etc.; G-Tube; Currently TPN-dependent.
Meds: Zofran, Pulmicort, IV Ceftazidime, Heparin (to flush PICC line), Claritin, Domperidone, Colloidal Silver (used topically), probiotics, homeopathy.