Runner's addiction symptoms? Really odd?

I get pains in my arms and chest when I am due for a run. I allow myself to run once every 3 days and by the third day the pain starts and I get headaches. I also get sluggish and moody. While running, the endorphins kick in and I can feel the pain go away. After I run, I feel awesome. Has anyone ever heard of such strong physical withdrawal symptoms from running? It's like being addicted to drugs for me. I've never done drugs, but I imagine this is what it is like.