Yes, I once had a failed startup, and ended up with $40K in credit card debt.
I assume you are personally liable for the business credit card debt. (As you generally can't get a business credit card without personally guaranteeing it). So, just to be clear on your situation, you are 30K in debt. (Regardless of what happens to the "business", you, personally, have 30K of debt).
Step one is to get yourself stabilized emotionally and financially. Good job on selling your car and moving out of your apartment.
These four servers that are sitting idle? Are these the ones that cost a total of $600/month, and you are contracted to keep paying $600/month through the end of January? (Am I clear on the situation?) Go and talk to the hosting company (the company you owe the $600/month to). In person. Not email, not phone, go sit down with a manager in person. Ask for mercy. Lay out the facts of your situation, just as you've done here. Say, "I know I owe you $600/month, and legally you have a right to that out of my last $6k check. Since I'm in this bad situation that I didn't expect, I'm asking if you would have mercy on me and let me out of my contract. Is there anything you can do to help?"
Next, write down a minimum monthly budget that contains the bare necessities: food, gas for the car, small gifts for your parents and friends to thank them for letting you bum off of them, the minimum payments on your credit cards. I mean this literally, write it down. On a piece of paper, or in a spreadsheet. You need to be able to look at the number, "$X/month", and say, "I can survive on that". Temporarily. While you catch your breath, and decide what next to do.
Next, I recommend you stop using debt as a tool to build your business. If you have a great money making idea that needs some capital, go get investors. Yes, you will pay the investors more in their share of the business than you would on interest payments, but you're making lots of money anyway, so what? And if the business fails, you walk away free and clear.
From a business point of view, the problem with debt is that is deadens the signal that you'd otherwise be hearing that you're on the wrong track financially. It's like some who suffers from leprosy, who loses the ability to feel pain in their extremities. The greatest damage comes not from the leprosy itself, but that people accidentally wound themselves (leave their feet in the campfire or something), and don't notice because they don't feel pain. Run your business on a cash basis, and you'll feel the pain of not being profitable right away, and make course corrections immediately. Run your business of debt, you rationalize things like you "have to" pay for ads upfront and invoice in arrears. Then you don't notice you've gone off course until you've gone over the edge.
You have a lot of ideas for things you can do now, and that's great! Find one that is going to be cash flow positive from the beginning. For example, those customer sites you could finish, or that product you could launch? Talk to people and bang on doors until you find someone who will pay you in advance, at least that portion which will be enough to pay for your minimal monthly budget for however long it will take you to get the project done. If your idea is good enough, if someone really wants it, they will pay upfront. If not, that's a signal that you need a better idea, something that your customers actually want. Don't go further into debt so that you can ignore the signal, instead pay attention to the signal.
OK, the 30K in debt that you're in now? Don't worry about it. Pay the minimum payments, and forget about it. Don't go further into debt, but for now don't worry about paying off the debt (aside from the monthly minimums) either. Sooner or later you'll get yourself back on your feet, make some money, and write a check to pay off the 30K. Until then, ignore it.
The CS degree? Don't worry about it. Employers and clients only care about what you can do for them. Now, if you haven't done anything yet, and you have a CS degree, then the CS degree is evidence that you're able to do things. (You at least made it through graduate school, and you're at least fairly smart). But you can show what you've done, and only a tiny, tiny percentage of employers or clients are going to care if you have a CS degree or not, as long as you can show them, as you can, what you can do.
But again, the very first thing to do is to put together you minimum monthly survival budget, and say, "OK. All I need to do, for now, is make this much to survive. I can do that". Once you do that, once you have your survival needs taken care of, then your stress lifts, your creativity comes back, and you will find it easy to start making money again.