so your problem isnt knowing what fingers to use, its remembering to use them when playing.. completely different to how I initially perceived your problem.
I would suggest slowing down and thinking about every single note for a while. play each note, stop, decide exactly what you're going to do next, then do that, then stop.. repeat. This way you practice exactly the correct fingering and get it into your muscle memory. Do at least 20 correct repetitions of a small segment - maybe one ascending octave of chromatic scale. Then take a break from the piano for a little bit.. come back and try again - will take you several small practice sessions before you start to feel the effect.
your brain will begin to process the idea without you having to consciously think through it. Once this happens you can start to go faster.