The OP is slowly committing suicide or giving themself brain damage on the way to the asylum.
It might take you a year to wean off that severe an overdose habit. But the sooner you start the sooner you’ll be moving back towards life, not towards death.
Greasy, yes, but eventually:
Yeah, the OP author is going to kill themselves. Nothing good can come from that much stimulant.
And yet they aren’t breaking any laws, nor are they morally wrong, at least as far as my morals are concerned.
So, the answer is, “yes”.
Agree completely with you that the answer to the titular question is “Yes”. But …
In the OP body he also asks
… is this drink going to have any severe negative consequences (already it is keeping me awake much longer at night) and are the benefits better than said consequences?
ISTM it provides no actual benefits to his writing, perhaps some illusory benefits to his writing, and great peril to his health.
And that was the question I chose to answer, since the other one had already been addressed IMO adequately.
It’s theoretically possible that the OP made his/her choice, and that he/she went for it in a big way:
Please check in and let us know that you’re still among the living 
Despite ingesting an overwhelming amount of caffeine, I am still amongst the living. I wonder who did buy all of it… and how much they’re willing to sell it for. 