So basically you're stuck between a rock and a hard place.
There are two different aspects to consider here. Short-term and long-term. I should also point out that I have some fairly opinionated views below. If this is something that irritates you I recommend perhaps skipping this post. I won't be upset.
Short-term
You need to be able to handle the basics of life. Food, somewhere to stay, etc. From what I can hear you're not pulling in any real money and it's really bad to use your savings for these expenses, unless it's for emergencies and a very short period. You need to make sure you're earning money. You say you can't find customers, and I believe you. Either this can be because it's a tough market where you are, or you simply suck at locating prospects and selling to them. At the moment, it's not really important which it is. Instead you should get a job. Preferably in IT where you have skills, but any job will do. You need to start earning money and stop eating your savings.
Long-term
When you have your basic needs met you start working on your side-projects as much as you find the time and energy for. A POS system is a somewhat large project, and I don't mean codebase only. It's not something most restaurants buy just like that. It will take some time finding the restaurants and getting them interested and gaining their trust in you and your product. I'd recommend starting a separate thread in the forum where you ask other POS developers (we seem to have several) how to get your first customers. I'm sure they could give you invaluable advice, and also help you avoid some mistakes. That said, it might also be a good idea to put your POS on ice for a while and see if there's a smaller project you could do, with faster access to paying customers.
So what I've written above isn't very romantic or fun. It's just the reality that many of us had to go through before getting our company of the ground. Not many short-cuts. Get a job. Earn money. Work in your project in your spare time.
You asked specifically about crowdfunding, so I'll address that too: Your desire to investigate this is simply based in desperation. Not only are your chances to be funded very low, it will take time and focus from you to make a decent campaign. And if you, for some mysterious reason, actually would succeed, you would have a number of investors that constantly would like to know what's happening with the project, when will they see something, and why isn't it done already, how close are you to a launch, and why don't you have this feature planned, and why didn't you do that feature that way instead, and are you really sure you need to sleep this month?