Is this a massive withdrawal?

Being a naturally (overly?) energetic type of guy, coffee (or perhaps the amount I drink) has been bad news since day one. I suffer the jitters, constant anxiety, and overall sense of not being relaxed, constantly. So I decided (with the help of a ferocious stomach virus) that it was a good time to start over. With all my insides all over my room, I figured this could serve just as well as a detox.

So here I am at the end of a fourth day of NO COFFEE(!!!), and I'm finally calm... physically. No more jitters, twitches or anything like that. But goddamn, if I don't feel like doing myself in. I'm dead tired, non-excitable, and pretty much feel real, real down in the dumps. And I've been sick before, maybe not to this degree, but I'm 99.9% sure it's the coffee's fault.

Does anyone with experience quitting caffeine/coffee know how long it takes before you finally feel like living life again? I'm so not myself... am I wasting my time with this shit? Thanks so much for reading over my rant... and thanks in advance for any advice you can offer

Peace