Calf Pain During Running. Pain In Hip And Groin, Difficulty Sleeping. Help

I used to run marathons, completed six, but in 2004 could no longer run because of an intense pain/burning that started in my calf, but then became more prevalent in my quad and hip flexor of my right leg. I ceased running, but took up hiking, biking, and skiing, but these activities also bring on this intense pain, to the point that it literally stops me in my tracks. I was trying to ride my bike up a hill, and my right quad hurt so much, I got off my bike and limped to a nearby fence. It even hurt to stretch, but the burn eventually lessened, and I was able to continue to ride, but couldn't put any stress/tension on my right leg. This same problem occurs when I hike and even dance. I can have a dull aching burning feeling in the quad, IT band, hip and groin for days following an activity, and can keep me from sleeping.