[Meatex]

If you are as you say: playing godly one game then the next game playing terrible then I don't think its a matter of being inconsistent as much as getting lucky when you feel like you play godly.
You have to look at those games where you think you were playing better than your best and figure out what you were doing that made it so and ask yourself why did you decide to do x? Was it because you scouted and reacted properly or it was just your timing etc?
Then look at the games you sucked at and see what you didn't do that you did on your games that you felt untouchable.

As for day to day ups and downs i find the most important things are good sleep pattern and healthy lifestyle including exercise and good food. Whenever I got lazy and didn't go to gym and got pizza for dinner I would play worse. When I didn't go to bed early and wake up early I played worse.