You need to work in training mode against some specific options dude.
For example, your third video in the match vs Scorpion. It cleary shows that you don't know the matchup, but you did some mistakes that cost you the match.
Against Scorpion you can't be in that range, mid to far, he can punish you for being on the same spot with Hell Fire, it's unblockable, and he can punish your attempts to zone him, Heat Vision or Heat Zap. You just DON'T zone Scorpion, so reduce the usage of those options to the minimum and you want to be in his face. You're using Superman, you have better normals and better pressure! Abuse those against him.
I know this is the obvious part...but don't drop your combos
I saw you do at least once wake up d2 and the Scorpion wasn't even jumping at you or something. The best wake up option, most of the times, is to just block. If you noticed that Scorpion player just spammed TP and Flip Kick, you even blocked a couple of times those moves...so punish them! Teleport Punch is -42 on block iirc and Flip Kick is -10, all those options and punishable with f23, which starts in 8f, into BIG DAMAGE!
Don't give up corner pressure, in the second round you got a combo on Scorpion into the corner, he was almost dying, and instead of going for 3 xx db2(or MB db2), after Scoop(df1) you went for a Rising Grab, thereforth giving up the corner and Scorpion left with that magic pixel. Corner game is great for Superman, his pressure gets better, due to no push back on db2, and his damage is outrageous. If you went for the option I mentioned, you would've won that round and Scorpion was in the corner in the next round, forcing Scorpion to get out of there using TP or a Jump, either options punishable by Superman.
Scorpions Super is really but really good, so you need to respect it.
I really can't stress this enough but ABUSE THE TRAINING MODE THAT NR GAVE TO US IN THIS GAME! It's great to test matchup specifics, like what can Superman pusnish against X or Y character. That's getting matchup knowledge and knowledge is power my friend. So go into the lab pick Superman and pick the ENTIRE CAST to test with! I've done that for Scorpion and to test how could you use setups for Hell Fire against each character in the game. Watch videos from other Superman players, you have loads of youtube channels providing replays, you have streams, so use those 'tools' to your benefit! Pause, rewind, take notes and 'playback' specific situations that you've found interesting.
If you are recording your matches then analize them, see where you did your mistakes and what can you do to correct them in the future.
Go into the lab, get confortable with your combos, get a BNB for Max Damage with or without meter, to inverse positions with Rising Grab, to push into the corner or for a untechable knockdown. Train midscreen, corner, anti air and air to air combos. Once you feel that you have those combos on the tip of your fingers move on to the next level - learning matchups and by learning matchups not only you'll get to know the cast better but also your character, Superman.
It's important to know your character, regarding combos or neutral game, because that way you'll play less atention to your character and more atention to the other players character. By paying more atention to the opposing character you'll be able to respond more quickly and with the adequate action much faster, than you normaly would if you were too focused on your character.
I learned that while I was stepping up my game on SSF4, at the time I reached a level were I felt really confortable with my character, regarding combos, setups and etc. So the 'exercise' was to look all the time at your opponents character instead of yours, and as time goes by you'll notice that your reactions have increased significantly. This applies to all games, not only SSF4, so get at it