Burning out your adrenal glands is no joke.
caffiene is a very addictive drug. Caffiene withdrawls can be a bitch. I was at a point where I would wake up and have coffee every morning, a couple of cups at least. I would head to the gm and take whatever pre workout drink of the day (1mr, no xplode, no shotgun, super pump, endo rush pick your poison) they were all fairly good for energy and getting through a workout. Then I would head to work (the mid night shift ) and to make it through the night I'd have a monster or a rock star energy drink sometimes 2. Throughout my day I was having close to 500 to 700 mg of caffiene everyday.
I did that for years. Overtime, caffiene wasn't so much of an energy booster as it was just a maintance to stay normal, without it I would crash hard, with it I was just getting by. Eventually I felt nothing at all. So much so that I could pound a rockstar and fall asleep a few minutes later. I said fuck it and just quit cold turkey.
I limit myself to a couple of cups of coffee per day and thats it. I don't use shit to workout. Just go and do it as hard as I can. Honestly I feel much better.