Uggghhh. Changing your main is so frustrating.
Lose a lot with your new chara > Get pissed, change back for a bit > lose some more because now you're rusty with the old one and start mixing stuff up.
I hate when that happens and then you start doing your new characters confirms with your old character and that doesn't work and you feel like an idiot. It mostly happens to me when I'm playing a game that I'm still kind of new to.