Hello, nice to have you here. The more people hanging out here educated in fine art, the better! 
If you work in the field you studied at all shortly after graduation, no matter what the field, you are doing pretty well at directing your career. If you stay in art and stay in Philadelphia, keep the gig and see if you can turn it into contacts. The dirty secret of school is that your grades don’t matter anywhere once you leave school. Where you went to school matters more, and it doesn’t matter much. The only benefit you’ll receive from your education is the certification that you completed it, and any knowledge and discipline you could retain from the experience. Those aren’t small things, you are ahead of people who don’t have them, so don’t take that as a denigration of them.
In regard to your class/accent being a hindrance (trust me, mine’s worse): My advice is to move, west of the Mississippi if you can. Once you get out here, no one will even know you’re from Philly, you’ll just be from back east. I know that moving is a big (heh) move, but if you’re focused on a certain career, you have to do those kinds of things.
OTOH, I’m not a person who was focused on a certain career, so I may not give the best advice. I work as a Unix Admin(among adminning other things when I gotta). I don’t have any real training in it, it’s not a field I studied in college (fine arts photography), and my art isn’t related to what I studied in college much at all. I’m as happy as one could expect to be. I luckily don’t depend on my passions to live, and former hobbies became professions by accident through people I knew and taught. I really couldn’t ask for more, but it was hard for the 15 years in between college and falling into a good place.
And on the inevitable third hand: My wife studied as a fine arts printmaker, and she actually works as a graphic designer. She’s umm, living with the graphic design day job, (the artistic part isn’t her problem, it’s really the corporate structure) but she really excels both as a fine and graphic artist. She works rather close to the field she studied, but has definite problems with her day job – sometimes by it being so close to her preferred profession, but not quite in it.
Tl;DR: Who you know and what you know are both very important. Cultivate both whenever possible, and be flexible in your goals if you have other concerns.
And etv78, the first rule of “Don’t be a Jerk” should be: When in doubt, apologize.
Even if you live in a world where hard truths must be said, sometimes you have to be contrite about imposing your world on others.