CUBC,
In your posts (which are excellent, btw), you keep referring to objects and activities outside of yourself. You mention diet, a lack of bad habits, lots of practice time, but then when consistency is the subject, you seem to go into a fog. Another poster said that if you figure out the consistency angle, you would be the first. That's in jest, but it's pretty close to the truth.
The Woim is going to say something here that may be taken as an insult or some form of snobbery so please don't read it that way. You, (CUBC) and all of us, must learn to know ourselves and our game as it really is.
When you're playing good and you're feeling good and that cue just sings in your hand - you literally love everything about pool at those precious moments and, from reading your post, it seems like you're in that zone regularly. But, when you're not in that zone, you can't seem to put it together.
This see-saw motion of up and down in the feelings and emotion department actually has only a small effect on your true pool game. I don't know your game but I'd guess you play at a consistently high level - strong B or B+, but when you're in the zone and hitting it, you feel like a AA+. Your emotions are playing tricks on you. It happens to all of us.
So, what's The Woim's solution? It's too easy actually. Assign game improvement to the hours of practice, and assign game assignment to your game playing time. Game assignment is to win, or place or lose with dignity. If you're feeling down, you know you're feeling down (don't fight that feeling or you'll be fighting yourself emotionally and trying to concentrate on pool at the same time) so adjust your goals and strategies to how you're feeling.
From my own perspective, The Woim has won many tough matches and games in a hard fought defensive struggle because I couldn't get into dead stroke to run racks.
When you know you're feeling down (and you need to focus on that) then be able to change your game plan. If you're feeling down, then you're probably not going to get the shape you want, or the speed control (notice when you're down you still pocket balls) so change the focal point of your game.
One last little comment, keep the game fun always.
Hope what I said helps...
Yours Truly,
The Woim