That's crazy that it took them so long to notice it.
If you're ready to completely ditch your friends and family for a 5 - 7 years, then just do it. Move at least several states away so that if you're picked up for doing something else, they won't be likely to extradite you back to your own state. I had a warrant out for me in Illinois once and got arrested in Texas, but since I was so far away they refused to have me shipped to Illinois. Because of that, charges against me were dropped. It might all be different in your case and I could be giving you horrible advice, but that's how it worked for me. Has Wal-Mart involved the police yet?
If you plan to keep using your real name, just explain the gap in employment as time you were going to school or taking care of your dying mother or something. Or maybe you were self-employed, doing some kind of labor work. Or you could have a friend of yours pretend to be an employer and give you an awesome reference. I've done that for friends of mine and its resulted in them getting jobs. You could even set up a voicemail for a fake company and call them back with the reference yourself. I bet if you look on the internet, there is even a service like this. Like you pay so much per month and they'll give you a good fake job reference.