Enroll iOS/Mac OS X Development Program while on iTunes Connect

The question is why can't I enrol multiple programs ?

I am right now enrolled as an iBooks Author but didn't yet publish anything, I though I would but didn't in the end.

I want to know If there's a way to enrol multiple programs and If not, How could I stop being an iBooks Author ?

I want now to begin the Program of the Development of iOS/Mac OS X/watchOS/tvOS but it says always an error and somewhere I read this message "The Apple Developer Enterprise Program and the iOS Developer University Program each require a unique Apple ID than that used for any other membership. You'll need to set up a new Apple ID and enroll separately. If you currently have an iTunes Connect account to sell another media type (books, music, TV content, or movies), you cannot use the Apple ID associated with that iTunes Connect account to enroll in any other programs. You’ll need to set up a new Apple ID for all other memberships."

What should I do ? Should I create a new Apple ID ? Because I prefer using only one for everything..

Thanks!