A.L.
From what I have read, once you ovulate, you get a flood of Progesterone, in turn, for some women, the added Progesterone has "relaxing" effect and for others (including myself, I just feel downright tired.
Also, Progesterone helps to relax the bowel so that in the event a woman were to become pregnant, her body could more readily absorb the nutrients (hence the slower bowel movement) in fact, your bowels do relax as it were...For some , this is all fine and good but for others, if you don't have enough fiber to help move things along, you begin to feel tired and constipated. Both could be contributing to why you feel more run down..
With your body suffering form chronic pain, the pain is a stressor of the body, which causes an excess production of cortisol (the stress hormone) that increase in cortisol can eventually further weaken your immune system... Hence, you continue to feel tired and worn out..
Once you ovulate, your Estrogen begins to drop off while your Progesterone begins to rise... With the drop in Estrogen (which controls the cortisol production) left to its own devices, you may find that IF you are having a stressful day, it becomes VERY overwhelming... and with the Progesterone on the rise... now, you not only feel stressed but oh so tired....
It's a vicious cycle to say the least..
Remedy... Although, you may be too tired to do it.. EXERCISE.. this will help to release those so badly needed "feel good" Endorphins.. Also, lots more fiber (as noted above) water.. DO drink up.. think of water as the gasoline for the body.. if you don't enough .... your body simply can't run right.... OR eliminate the toxins as needed (especially when your body is still trying to heal itself)
Lastly.. a little meditation goes a long long way.. even if just for 15 minutes.. try and step back, take a moment to calm your body ... I have found these tools to be helpful..
Of course, good nutrition..... I know it's hard around the time of one's period, as you might be craving sweets.. you aren't imaging that.. that is also thanks to Progesterone, which makes us more insulin resistant (esp IF we already partake in insulin raising foods)..... therefore, prior to our periods, the cravings can become worse.. as well has yeast infections more prevalent, which is become we becomes more alkaline right before our periods (as oppose to acidic) which in turn... yeast just love........as you can imagine, they thrive more in alkaline than an acidic environment)
Ahhhh being a woman :)
Start with one modification at a time... then starting add one each week... see if some of the suggestions make life a little better and go from there..
also, Dr. Elizabeth Vliet has a few books out relating to women and their hormones, they are packed with lots of good info!
good luck to you