I Have Continual Pain On The Outside Of My Upper

I have continual pain on the outside of my upper thigh at the point where it joins my buttock. I have been doing a lot of stair walking for training as I want to climb the statue of liberty in July. I have increased to climbing 250 stairs at a time, approximately 5 times a day.
Hoping this pain will go away as I want to keep doing the stairs but am concerned I am continuing to aggravate area.
any help/ideas would be appreciated.
Thanks Ruth