Obviously he did NOT do the right thing. There is nothing wrong with admitting a mistake. But it was not an entire loss - he was able to grow with the experience and realize that the lifestyle being sold isn't for everybody. Right, it is NOT for everybody. My advice is that he follows through his new found learning and tries to go back to a job. He is a more mature person now, and will be able to find one eventually.
It's still not obvious to me that quitting the job was the wrong choice. The mistake was what he did afterward in failing to find an alternative source of income. It's a common mistake to quit without an adequate plan, so that is a good lesson learned.
You coded in C++/Javascript for clients that don't pay. Go to college and learn Computer Science. This will allow you to code for clients that pay. Some of these companies will suck, but some of them will be very good places with great coworkers and a lot of creativity.
The art diploma will be useless. If you have a CS degree, you can have a day job that pays well and maintains your art hobby. Later in life, if you art hobby "takes off", you can drop out of computer science and become an artist full time.
The point is: CS will give you a base that you can use for your entire life and keep you going, allow you to have a family or even be single and reasonably well off.