If you want to kick caffeine, I recommend switching to caffeine pills and continue using as many of them as you need to feel normal, then start ramping down the dose. Since pills are discrete it's hard to cheat. When I do this I usually start at 400mg (sometimes 600mg) a day then over the next month ramp down to 100mg a day until finally going to zero. It takes me about a month before I can function normal with no caffeine.
...then a few months later I decide to start again. Oh well. I've done the above about half a dozen times. It's fairly easy to defeat the chemical addiction which I experience as you describe (really awful headaches, fatigue, lack of concentration, etc), but eventually I'll pick it back up to get a little extra edge.
Something I used to do is make a big pot of coffee and sip on it throughout the day, which was very hard to regulate (and it was also just too much caffeiene). Now I make a single cup of coffee in the aeropress and I use 16 grams of beans which i weigh manually. And I only have one cup of coffee in the morning instead of multiples throughout the day.
Point is, weighing beans and using the aeropress helps me keep my dosage consistent so I don't go overboard.
Decaf is pretty good these days; When I don't feel like ditching the actual cups of liquid I swap over. It's certainly what I reach for in the afternoon if I want another coffee for whatever reason. Might be another option if you still enjoy the ritual of coffee making and consumption.
I've tapered caffeine successfully by measuring out instant coffee. This works pretty well for managing the physical effects of caffeine withdrawal, or at least spreading them out. Basically, I 1) committed to only having the same exact amount of instant coffee, at the same exact times, every day, and then 2) every so often, reduced it a bit. Then I switched to a very moderate amount of decaf (which, yes, has a little bit of caffeine in it, but not enough to cause me problems).
I did this because I was getting withdrawal headaches most mornings, which is an unpleasant way to begin the day- I wasn't even drinking that much caffeine!
I never really liked coffee, but I drank it at work just as a pretext to talk to other people.
I didn't have a coffee maker at home at that time. So I started getting headaches on Sunday. I made the connection eventually, after my headache completely disappeared 20 minutes after drinking a cup of coffee with a friend.
It's telling that both people recommending this method have seen it fail multiple times, and are somehow rebranding those failures as successes. Every time you quit again "successfully" was because the previous attempt failed.
While I'm not aware of efficacy studies of different methods of quitting caffeine, cold turkey seems most effective for nicotine and a few other stimulants.
The irony isn't lost on me, but we're recommending a method to safely wean off the substance to prevent having withdrawal symptoms, which have prevented me from coming off from caffeine in the past.
I wouldn't frame starting up again as a failure. Quitting short vs. long term are two different things.
...then a few months later I decide to start again. Oh well. I've done the above about half a dozen times. It's fairly easy to defeat the chemical addiction which I experience as you describe (really awful headaches, fatigue, lack of concentration, etc), but eventually I'll pick it back up to get a little extra edge.