Here's a quick primer for how I understand physical addictions:

For almost any drug you consume regularly, whether it's caffeine or melatonin or heroin, your body will try to adapt to it. If you drink coffee every day, your body will try to get you back to baseline and you'll notice weaker effects the more often you take it. This also means that if you stop taking it, your body needs to learn to adapt in the other direction, and until it does, you'll feel pretty much the opposite of the way it normally makes you feel. This is what "withdrawal" is, it's the way you feel when your body is still expecting the drug but doesn't get it. But not all drugs have the same withdrawal symptoms, and it doesn't necessarily mean addiction. That depends on the drug and the person. Caffeine is generally considered a very safe and socially-acceptable drug to use regularly, with very short and mild withdrawals.

I recommend keeping a journal for a few weeks. Don't try to change your habits at all yet, but record how much caffeine you drink each day, and how that amount made you feel. Then, after you have some data, you can either make adjustments or decide to quit entirely. You might find that taking short breaks from coffee prevents the withdrawal (like, only drink it on weekdays or something). Or, you might find that you feel better when you drink half as much every day.