I guess that’s why I put “designer quality” in quotes, because even the quality among designers that have a college degree varies quite a bit.
This is not meant to say your design abilities are subpar. They very well could be great, but simply because your’e doing certain tasks, wouldn’t necessarily say you’re qualified. I think as @Just-B said and as you also said, by taking a few classes it may help you to better see where you stand.
I also will say, there is a lot to learn and know that you may not even learn in school that is also paramount to being a designer. Heck, even after 20 years doing this I’m still learning things.