If I may suggest... make sure you brush your teeth after drinking coffee. Taking advantage of it now (early in your addiction), will save you the trouble of having to get your teeth whitened professionally.
Any number of the OTC toothpaste + whitener will work. My favorite being Colgate. Some times I use AIM, but I have clear/white braces on my teeth and AIM turns them blue when I brush. Thankfully it rinses off, but still. Yeah, having braces, I had to watch my consumption of coffee. I now drink it about once a week, if that. I'm glad I don't get the headaches anymore if I hadn't had a cup in a few days.