What Causes Chronic Backache And Migraine While On Sprintec?

I went on Sprintec 28 last August due to periods every 15-18 days with worsening cramps/backaches and migraines, all are unmanageable except through narcotic pain meds. It didn t work, I have tried Lo Loestrin and now Minastrin and started my 3rd period in 28 days today with another headache after only 1 day of 4 reliefe of last cycles headaches. I have very few days without cramps and backaches and headaches. I hardly function. I have osteoporosis at 45 due to 30 years of anorexia so I guess stopping my period is not a good option. But how do I manage with this poor quality of life/decreased ability to function?