Leviathan -
I have no wisdom, as I'm right in the same spot myself. I am sitting in my office right now and in front of me is a sticky note that says "Start No Sugar - 3/23/15"...Um, so, I guess I'll throw that away...
It is very similar to the period that preceded sobriety for me. I'm good in the morning, and then - just like you - late at night I'm curled up watching a movie or reading a book and DECIMATING a pile o' candy. I have never eaten candy in my whole life. I've always been a "savory" type girl.
So, I'm going to have to just do it. We certainly have the tools and resources, just reapplying all we've learned in other quits to this one.
I will suggest that maybe the caffeine and sugar are two separate quits. You will have both physical and psychological responses to each one; my coffee consumption is no where near yours, and if I don't drink it I have a throbbing metallic head-ache that makes it hard to even turn my head to the side to look over my shoulder!
I also suspect that we'll have to go total abstinence on these. Tapering has never worked for me on anything - just my pirate nature. I realize that sugar masquerades inside catsups and sauces, and I don't have the energy or incentive to go that far, but I can certainly just decide to quit candy and obvious sweets...
I'm sure that this is impacting my energy levels, and I would like to drop ten pounds so that I can walk around feeling gorgeous all the time (I feel gorgeous once in a while now, but only when the light is just right...LOL). The sugar replaced the alcohol immediately, so since quitting drinking I've lost.....tah-dah....a total of two pounds! This is absolutely ridiculous as I stopped imbibing thousands of extra calories, and started walking my dog one to two hours every day... it has to be the sugar replacement which is preventing weight loss...(duh!)