I started around two or three years ago, once I picked up my hobby of drawing again. I posted some of my artwork on some sites that do the job of printing it on merch like phone cases, t-shirts, and pillows for you. Since I don't promote my stuff and I have few projects to show that kind of vary in style, I only receive a few dollars every now and then. (One out of those 10 sites have no minimum payout requirements, psh.)
Now I'm writing, whether it's informative articles or creative writing. I'm making a decent amount of pocket money. But I hope to greatly improve on my writing and artistic skills to eventually create an interactive fiction that the audience I target will like a lot. It also helps that I can create my own websites so that I don't have to pay anyone else to start a site meant to host my writing/art portfolio.
Why? To have money for food, for bills, for student loans. Hopefully increase that earning so I can provide for a family in the future.
It's good you're determined not to give up. Some people don't earn anything for years, but that's because they're putting their time and effort into finding something they can stick to and earn a lot with. You'll find your specialty one day and one day you'll be earning $5/day, then $20/day, possibly more. Be persistent and it'll pay off!