Is it me or the champ

I was previously a support main and decided to step back a bit and I’m trying to play Gwen because I like her dash and true damage however she just seems really weak. I’ve looked at videos and invested a bunch of time into her but I get the same outcome. I’m weak until I have a few items but by that point the game is already determined. I just wanna know if it’s Gwen that’s weak or me.