Yes, this could be adrenal insufficiency from too rapid a taper off the Prednisone.
Some find taking Vitamin C & Vitamin B5 (Pantothenic Acid) supplements helpful to support and "feed" the adrenal glands...
Another option is an herb called Ashwagandha, it is a gentle way to support and balance adrenal function.
Also, make sure you take a good probiotic (Acidophilus & Bifidus) to help your gut recover from the doxycycline. If you are still taking the doxycycline, take the probiotics 2 hours after each dose of doxycycline.
Chronic Lyme, Bart., Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut dysmotility & non-specific inflammation, Lupus, Osteoporosis, etc.; G-Tube; TPN-dependent
Meds: Flagyl, Zofran, Acupuncture, etc.