Severe knee pain & crunching for 3 month. Now full leg is hurting & aching painkillers not helping, what can I do?

See doctor. Sounds as though u may have injured cartilage in knee (meniscus) or (if you're significantly overweight) may have worn down cartilage at ends of femur and tibia (arthritis). See fp/orthopedics/sports med doc for thorough exam, probable mri, possible knee arthroscopy & other appropriate treatments.