Here's some more info: Smash Practice has a video about psychology (they are working with that guy to make more of them) and they also have some videos about how to teach yourself from your mistakes.
https://www.youtube.com/channel/UCtGeosEjh8wfMZifNfhospw
There is a player named JpegImage about 2 hours from my city. He's considered semi pro at least. His advice on solo practice was to watch videos of a pro that plays your character and to write down or mentally take note of which moves are being used at what percents, how they are spacing, which combos keep happening which stages they strike to, any habit that you can notice.
Also you can compare how you are playing the match up
to how another descent player is
to how a pro is.
And that's all my advice.