Whew.
Well, you're not a failure. You're making a living by working in the academic field that you love, without having an advanced degree. That's actually something of a feat.
Yeah, you can certainly bump your prices up a few bucks. That's not going to change the basics of the problem here, though. You need to make tens of thousands a year more -- and hold your spending steady -- to get out of debt and build yourself a retirement.
To make enough money to get ahead, you're going to have to do work you're not (presently) interested in. If making up problems interests you, then you could possibly work up an interest in programming -- that sort of algorithmic thinking is what it takes. And if you can learn to do it on your own and demonstrate your ability, (and the economy holds up) you can get much more remunerative work. Other math-friendly fields (accounting & so forth) tend to require credentials that are expensive in time and money.
The financial trouble here is you need to make a lot of money, and to do that you have to bring something to the market that people are paying a lot of money for. Tutoring (unfortunately and unfairly) just doesn't bring in the cash on that scale. I think your perception that you've pretty much maxed out your returns on it is probably right.
The other trouble here -- and this may be the one to solve first -- is that you just are not happy where you are: you don't have a community that feels supportive, you're discouraged and tired and isolated. It may be that you need to go back home, if that's at all possible, and take on any sort of work you can find -- washing dishes, mopping floors, whatever -- and find yourself some some support, before you can go on to a new thing. Or maybe you can find people where you are. Everyone needs a few people in their corner rooting for them -- that's not a weakness, it's just the way humans are built. We're social animals, even us math types. It doesn't have to be partying, unless partying is what you want to do -- just people to hang out with, cook with, go for walks with, brainstorm and laugh with. Whatever. You need a social life. Everyone does.