Saku: by no means is your art terrible. It's really great, actually. You've got a really great talent on your hands. I know that must be useless because I know exactly where you're coming from, so all I can do is encourage you to continue drawing and to branch out in terms of what you draw, and art courses are great for that. Also try not to compare yourself to other people, especially with what you see on the net (it gets me down a bit sometimes too ;p); try to take inspiration for new drawings from them instead.

Don't get too down or frustrated about it, keep up the good work!