Referencing makes a lot of sense with helping improve ‘art’. Think of When you practice in art class the warmups they give where you draw a picture. I think the most informative critique is when there is a reference to compare to.
You're a good artist. What really caught my eye was exactly how spot on your duck drawing was to my non-professional eye.
I hope you keep at it.
EDIT: I just reread your comment. I don't mean to make it sound like recreating other people's art is the problem. Of course practice is important and existing stuff makes a comparison easier, I'm 100% in agreement with you. Please don't stop. But i think it's also easy for someone to have seen your art and assumed it was original. This is a place where showing off original work is accepted and "practice" doesn't indicate originality one way or the other.