You get a job because you need money. That's reality, and there is no more than that to it. You do something someone else needs to get done, and they pay you for it. Me? There isn't anything on the planet that I can do for 40+ hours a week year-round and not get sick of. Including pottery, or lying on the beach drinking margaritas.
I have a lot of life experience, very good career-in-Washington DC jobs, minimum wage office temp jobs, minimum wage fast food jobs, fun art jobs that don't make much money. And I make and sell my own art, which is fun but doesn't even begin to support the family-- but I don't need to support the family right now, I have a spouse who does that.
The one thing you don't want is a job you hate. So don't apply or train for "cubicle" jobs if you can't stand being in a cubicle for more than 10 minutes. Cubicle jobs do have the advantage of being climate controlled. If you ever have a work-outside job (like picking blueberries, which I did one summer), you will appreciate the advantages of that.
There are career options other than cubicle jobs or pottery. Just make sure that whatever you do, you aren't operating under the assumption that your parents are going to be your source of income for the rest of your life. I guarantee you that isn't going to happen unless your parents are idiots. Think about it... how long would YOU support an adult who shows no interest in making enough money to support himself?
Here is why your parents are less than enthusiastic about your plans to live at the poverty level. Living at or near the poverty level can be a very ugly experience. Glazes, clay, studio space, kiln-firings, enough space to store your finished work, and a camera to photograph the work you plan to sell all cost money. And there are a lot of other things you can't have if you have no money: health care (suppose you slip on some ice, break the arm you use to throw pottery, and can't afford to get it X-rayed or set? or you get strep throat or worse and can't afford to buy the antibiotics?), a roof that doesn't leak, clothes that don't come from a thrift store, a date that your date doesn't have to pay for, a computer & software that isn't several generations old, phone service, the ability to pay your heat/water/electricity bills, a car so you don't have to live walking distance from a grocery store and you don't have to use public transportation to get your art to an art gallery (imagine carrying boxes of pottery on a crowded city bus because you can't afford a car or shipping), and... the ability to buy a decent quality interview suit if you need it.
Eventually, you may decide that getting to spend your life making art isn't worth the trade-off. Or maybe it is worth the trade-off. Finding this out sooner rather than later would be a good plan.
Maybe before you spend more time and money in school, you should take a couple of years off from school and try supporting yourself as a potter. You don't need an MFA to do pottery as a career, you need to make large quantities of competent pottery. You need access to a studio, you need to make a body of quality work, you need to learn how to handle your own finances/accounting, and you need to learn how to do the sales / marketing work and do it.
Write a formal plan for how you are going to set up your pottery business. Figure out how much pottery you need to make to support yourself, and how you are going to make that happen -- how much time, how much materials you will need to accomplish that plan. And set a deadline for when you will stop and go back to school if this isn't working. For example, if by Jan 2013 the pottery profession isn't bringing in enough money to support you, this will be very obvious to everyone. Hopefully including you. Then finish your education, and pick a major that will result in a career that (a) brings in enough money to support you; and (

doesn't have you doing something you hate.
BTW: If you "hate" everything except pottery, the problem is you. Find some things to cross off the list of things you hate.
There are plenty of jobs out there that don't require being in a cube. Drive a truck or a bus or ride an ambulance as an EMT. Be a forest ranger or a policeman. Wait tables at a restaurant, or be a chef. Electricians, plumbers, and tile intallers don't spend their lives in cubes. Neither do surveyors, housing inspectors, real estate agents, prison guards, daycare personnel, or bricklayers. Pick something you "hate" less, and make yourself do it. And... continue to do pottery as a hobby on the side. Maybe someday your work will sell well enough that you will be able to quit the job that you do because you need money to live on.
"Art Teacher" is one job that doesn't have you in a cubicle for the rest of your life. While teaching art is VERY different from making your own art (you MUST like students, and you MUST have reasonably good people skills), that is a support-yourself job that a lot of people who are "called" to do art choose.
Good luck. If you really want to be a professional potter, do it. Now. Do it while you are still young, and you can still change directions if it doesn't work for you.