Okay. I've never heard of somebody only drinking one caffeine drink a day. I feel like if that's all you're drinking it's such a low amount of caffeine you probably don't even need to quit.
Most people drink a lot of caffeine a day, and for some, every single drink they have has some caffeine in it. Those are the people that might need to cut back or quit or cut down to one caffeinated drink per day, which would be a good goal too.