I tried for a long time. Sold my Wacom a couple of years ago to make money, and haven't really done anything since.
I still love to do digital art and graphic design. But unless I've got the magical combination of hydration, caffeine, being well rested, having no stress, being in the zone with background music, and having a flash of inspiration; I basically just waste hours trying to do simple things, or I make tweaks until something seems right.
I have a small handful of digital paintings, but nothing I'd care to share. My DeviantArt days are long gone.
I'd say that if you're making some money off of it, then you must being doing well and have some good work. Kudos to you, that's genuinely an awesome thing that you should be proud of. :)