Well i always thought i kinda sucked haha. There will ALWAYS be someone better, guaranteed! It's a good thing, because there's always something to strive for. The key is self-motivation and obsession; are you obsessed enough about visual things, do you stare at stuff like rust and leaves and people's noses, anything and everything your eyes can eat... Illustrators are by nature very inquisitive. If you are obsessed enough, the years of practice fly by. (Kind of like videogames! afdshfkads hahaha, oh, the time i've wasted! ;A; )
I've fooled with digital since i was old enough to work a mouse, so i can't say classes taught me everything, they just taught me it faster. Before, i started by googling tutorials. (Lol i still google tutorials, like on cgsociety and conceptart.org) But learning Photoshop is no match for good old-fashioned drawing skills and color knowledge.
So, stalk those tutorials/books first instead. Also stalk people on buses and animals at the zoo. I know people who always have pencil and a little sketchbook with them.