Saturdays, my "off" day

I noticed that for the last 2 months, Saturdays, and Sundays too, have become my "off" days. The weekly dexa dose for Monday, Tuesday and Wednesday really give me the "high" until Friday and first thing Saturday, I will wake up all "zonk" - the head is dense, the eyes can't focus and ears deaf; my body cramps up and feels twisted. Awful feeling! My mouth is constantly dry despite drinking plenty of water. The fingers and toes are numb and sandy. My mood crappy! Social interaction is best kept minimal. 
By Monday, there is slight improvement and when I restart the weekly dexa dose, I will re-enegise again. What a roller-coaster!
As long as I know what is going on, I can cope. Hopefully no other more serious complications, I have read enough to know it can be worse. So I am very thankful to be getting by reasonably well. Still enjoy eating, and this crazy fixation with cleaning and clearing. I will be hitting the storeroom and wardrobe next.   
(At 20mg for three days a week, I felt super-charged. At 16mg for three days a week, still energized but more subdued.)