Most doctors will tell you that a small or moderate amount of caffeine has a positive effect on athletic performance. Now you have to define moderate. Most will say that the equivalent of up to two cups of brewed coffee is OK, but that varies with some people. Your plan of reducing the caffeine is the most successful plan for most caffeine addicts.
I like a cup of coffee once in a while, but I am much more a fan of hot tea. Fortunately, hot tea has only about half of the caffeine of coffee. Also, with tea you can brew it lighter or heavier, just depending on your mood. My mood has me drinking three or four cups of hot tea per day, not particularly strong. It turns out that the liquid is kind of beneficial for keeping your kidneys washed out, and as long as you don't get too much caffeine going, it's OK. I drink caffeinated hot tea prior to 5 p.m., and decaffeinated hot tea after then.
My apologies to my Mormon friends.