I went cold turkey after developing a facial tic and realizing I was consuming 1000 - 1200 mg of caffeine a day (mostly coffee, French press and canned, with some energy drinks too). I was 100% not aware that caffeine is physically addictive and causes receptor changes in your brain. Aside from withdrawal symptoms (joint aches and pains for me), the fatigue didn't fully go away after several months.

What did "fix" it was bringing it up to my doctor at my yearly checkup -- I explained that my mystery joint pains from a few years ago were almost certainly physical symptoms of caffeine withdrawal. This led to "why in the world were you consuming that much?!" questions and an eventual diagnosis of adult ADHD (likely lifelong and never diagnosed). 10 mg of generic ritalin twice a day and not only is the no-caffeine fatigue gone, but I basically don't tolerate caffeine anymore and have zero desire to consume it. Fortunately the local coffee roaster has a decaf :P I love coffee with or without the caffeine.