Wow, what a bunch of jerky responses. OP wasn't whining or acting entitled or asking you how much more you make. He asked for info, and a lot of you picked on him. Make fun of the poor kid- very 7th grade.
There isn't enough info there for us to really say what you're worth. But don't stay at that job at that pay rate any longer than you absolutely have to. Unfortunately, if you've worked there this long, odds are decent that they see you as an underachiever, regardless of whether you are or not. This may make it difficult to convince them to give you any more than they are now. The harsh truth is, hard work doesn't tend to get one respect in the eyes of many restaurant owners. One possible way for someone with GM experience to make a lot of money is to make an arrangement with the owner of several franchise stores that you will get to buy a store from him as a condition of your employment. It's not uncommon for them to back out of it, though.
FINISH COLLEGE. Even if you can't get a degree in something you want. Any degree is better than no degree- it will get you a start in something better (assuming you're not interested in a lifelong career in the restaurant business). I would not recommend taking a year off unless you absolutely must, because a year off often turns into ten years off.
It sounds like you need more confidence, which could possibly be holding you back in management. If you're lacking skill in dealing with customers or speaking to your employees, get some help with that from someone whose behavior you respect. Exercising authority appropriately is an art, and it takes practice and understanding. In most situations, you don't want to get people to do things, you want to get them to WANT to do things. When you come from that perspective, you can also work with the idea not that the thing needs to be done, but that the thing WILL be done, but you don't have to be pushy or disrespectful. You also inspire them to do things right even when you're not around. Note how the third example is better than the first two:
--"We have an ID policy. I need your driver's license." Don't order the customer.
--"Can I see your ID? We've been getting a lot of bad checks lately." Don't accuse the customer.
--"If you don't mind, with checks, we're just supposed to take a quick look at your ID." Make the customer a partner in an impersonal necessity of business. Don't ask them, don't order them, just know that the customer is reasonable, and he will have no problem letting you see that ID before you take their check. Tone of voice and body language are as important as the words, but they're hard to put into print. Diminutive words like "just" and "quick" make it sound like a small hassle and like you know they're not trying to scam you.
Also, suppose you have an employee who knows how to do something right but does it her own way anyway:
--"You can't do it that way. You need to do it like this and like this and like this. Got it?" Stubborn doesn't always equal stupid. And maybe they actually have a good reason you haven't thought of.
--"Hey, stop doing it that way and do it right. I've shown you time and again, and I'm tired of getting griped at." Stubborn people are usually not easily intimidated, so all this approach does is create tension where it's not usually necessary or helpful. Only once in a great while should you ever need to talk anything like this.
--"Hey, uh, do me a favor. You remember that other way of doing that we showed you? Well, that's the way I'm supposed to have you do it, so if you could do it that way, I'd appreciate it, ok? I know you have reasons for your way, and I appreciate that it saves time, but we really need to get that thing clean every day. Can you help me out with this?" You have to do this in a confident manner so you're not begging, you're telling them you know they're on your side. Many people will respond positively and end up, in fact, on your side, wanting to please you.
To be an effective manager, you have to do more than just make good pizzas and balance the books - you have to get your bosses, crew, and customers all on your side. If you find yourself not really interested in leadership (nothing wrong with that), you should get out of the restaurant business ASAP, because usually the only people who make money in restaurants are the leader types.