That's great, Newhope. I have started running since I quit drinking 11 days ago. I hate it, but I am making myself do it. I know if I keep it up, I will start to like it, like I used to. Before I became an alcoholic (in my 20's), I ran 2 half-marathons, barely training either time, like you. It amazes me that I was able to do that, because now I can only go about a mile before I have to start walking. I blame that on the alchol and smoking (which I quit about 6 months ago).
It's great you found something to substitute for your drinking. Running does give that natural high. Good luck on Sunday