Deep breath - it's not as bad as you think. Hubpages does not differentiate between your work and someone else's work. They label it a "duplicate" if it is on the web regardless of whose work it is.
It is your choice whether you wish to leave your "duplicate" hubs on your account or not. I have two "duplicate" hubs that I have left because they are my work; but, they do appear elsewhere.
So...the choice is yours whether to continue to leave it on Hubpages or not.