Jordie it is always hard to try to give job advice to someone else because everyone is so different. What works for me might not even make sense to you, or what works for the next guy might seem like insanity to someone else, so with that said all I can do if offer my opinion based on what I myself would do if I were a young 18 yr old guy like yourself just getting out of college, not sure what I want to do, and 50K worth of debt.
First off you are NOT being a leech to your parents. If it makes you feel better then throw a few bucks to them for rent but stay there for a couple years while you get some of that 50K debt paid down because once you are out on your own you will not have the chance to pay the debt off like will be able to now. Since you don't know yet what you want to do, and like you said being 18 right out of school it's gonna be hard for someone to trust you with their marketing budget right now because of that. So What I would do...
I would go get just basically ANY job you can get right now. No matter what it is even stocking shelves or what have you, because if you stay at home for 2 years then you could get that 50K debt paid down dramatically with even a low paying job because you would not have any other bills to pay. Then after 2 years or so you could then start to look into starting up your own media business because you would have most your debt paid down, you would no longer be a 18 yr old just out of college so people would be a bit more apt to consider you for their marketing needs, but the main thing is you would not be starting life 50k in the hole. Then you could actually look for something that you truly enjoy doing.
Like I said that may not be the best advice for everyone, but that's what makes sense to me personally.