I dont think a new char is just gonna fix everything for Espy or Illmatic.
Of course it won't automatically mean you start winning, but it is the first big step a player needs to do if they honestly want to start seeing money. Swallow the pride, pick a better character, and go back to the lab. Put in those hours, learn everything, keep your old character for any good pocket MUs and keep them solid, then you can focus way more of your attention on getting better.
Remember, you're playing catch-up to people who already put in the work for a long time and still do.
If you can't give up playing your character when they aren't viable, tough. I pretty quickly came to the realization when I was playing that Peach wouldn't pan out in the end. Too many issues, too many bad MUs. Some Houston players just told me I needed to put in the work and transcend the barrier. Honestly the smarter ones told me to trade up. I decided after fiddling around with this that trading up just wasn't that fun to me, and neither was the game really. I retired and have no johns.
You can still be a respectable player and have fun with the game and even win sets with good players no matter what character you use. But to consistently be a dominant force in the game, you have to submit to reality.