1. It seems to be you are suffering from a condition called Meralgia paraesthetica
2. It occurs whenever the superficial nerve
on outer aspect of hip gets compressed.
3. causes can be tight belts or pants or lying on same side or pressure against hard surface, sudden weight loss
4. Its a self limiting cause. Wearing loose cloths around waist, NSAID's +/- neurotonics usually gives relief.
5. If problem persists get examined by orthopaedican +/- neurophysician and proceed.