Hi Again,
I think what you and many others need to do, is to stop aiming so high initially! There are a million fashion labels out there in the world other than the luxury well known designer goods that everyone wants to work for. If you had the skills and experience needed to work for them, they would hire you instead of palming it off and rejecting you on something as a scapegoat and non-personal such as you don't have the associated degree. Yes in the upper elite sector LV, Chanel and Dior do value education (and a first class one at that) but they also value contacts, experience and networks more so!
I think you should finish your arts degree like you have stated and then look at successful smaller labels that are lesser well known to most people (but nevertheless well know to someone in the fashion industry), contact them and offer to do volunteer work experience. Even if you are simply sweeping up the showroom after hours or some other mundane job - getting your foot in the door is key! Network, network and network! From there by the time you have finished your art degree you might look at getting something full time.
I would say do about 5 years learning on someone else's time before you jump ship to open your own business. Work for smaller places where you will be exposed to and therefore learn more about fashion business than big organisations where you only see one aspect of the business.
To have your own business, the only person who will care about your resume - is you! Don't bother striving for years to reach the top labels - you don't need to market and sell yourself!