severe lower abd pain

have a 17 year old pat. who has had severe lower abd pain for the past 4 year..becomes worse with on set of menses. she has had all medical test showed really no problems.  has missed much school due to her problems. pain is so bad she is bent over at times.  only relief medicalion and heat.

Her symptoms. nausea daily, hard dry constipation(balls), Very cold hands and feet in the day and hot feet at night. when she was young her feet would peel, hands very dry, extreme fatigue, sweats under arms...excess. temporal HA, earaches, grinding teeth, gas abd bloating, low back pain... itching, pain in the neck and shoulders with menses, her cycles every 27 days, last 5 days, 1 light  heavy, 1 light 1 spot. has PMS, unable to go to school during that time....Has had some problems with light headedness when getting up from a seated position.  Sleep is solid through the night. 

Pulse....Left. cun slippery wiry. with dong b/w 1/2. guan deep, chi deep right cun lower super/thin wiry slippery, guan, thin wiry/slight slippery/med , chi deep thin. My thoughts

Da huang huang lian xie lin tang, but better yet....a form of xiao cheng qi tang./da cheng qi tang..

what do you feel as my approach and with the pulse would you start this plan of she has been suffering for a long time. I think some modification may be necessary as she is so dry......your thoughts on this would be greatly appreciated.