I Started Having Pain In My Upper Tibia Right Below

Question: I started having pain in my upper tibia right below my knee a few months back. It wasn’t too bad at first but as I continued vigorous training and running routines, the pain became a lot worse and severe. I eventually tried to test it for 5 weeks then got back into my routine. That did not help and my situation a month after the rest is 10x as worse. Now a specific spot on my tibia hurts to touch and sends pain down through my leg to my ankle and foot. Now it interferes with every day tasks because it hurts to walk, I cannot go up a flight of stairs, nor can I run without my leg feeling like it isn’t stable and that it feels like it is going to snap. Not sure what exactly is wrong but I would like an idea. I do overtrain and I put a lot of stress on my legs on a daily basis. But now I cannot do anything on a normal basis. Even sitting in my chair my leg is throbbing in pain.