First, you're not addicted to coffee, you are addicted to caffeine. Remember that caffeine is a DRUG.
Second, switching from a diluted caffeine intake (such as coffee or soda) to a pure intake (pills) could lead to you worsening your dependency on caffeine. Think about it: you drink 5+ cups of coffee, but you probably can't drink 10 everyday.... but you CAN pop another handful of caffeine pills quite easily.
If you look to the past, you'll probably see that your caffeine intake has been increasing, but the effects have not been intensifying. That's because your body builds a tolerance to caffeine over time. I used to be super jittery after 3 shots of espresso, but now (after 2 years of heavy consumption of coffee) there's not much effect.
My advice: don't switch to caffeine pills to fix your problems. They'll only make it worse because it will allow you to consume more caffeine in purer form at a faster rate than drinking coffee. As you consume more on a regular basis, your body will build a higher tolerance. You'll find yourself taking more and more caffeine pills to avoid the headaches.
So don't take pills on a regular basis, and start decreasing your coffee intake. I've set my limit to 2 cups of coffee or 2 shots of espresso per day. Drink more water - you'll feel way better than when drinking coffee.
Everything is fine in moderation.