You're focusing too much on what you don't have and you don't realize what you already do have. And what do you already have? Ask yourself that, acknowledge your resources and make the best out of it. That's what an artist does.
Don't focus too much on the technicalities of drawing. What you should focus on is the same as what everbody else has said: Drawing. Just draw. And starting with realism first will help you a lot, so trust your eye, not your imagination. There's a big difference between what you see, and what you think you see.
You most likely won't see this post, but even if you do you probably wouldn't understand/listen to this. Having read how you responded to all these helpful people, your attitude is truly offending.
Look at other drawings. Look at tutorials, even better, try to look at step by step drawings(Ahahahaha, I myself do not know how to draw anything except anime or manga and I can't copy some of their positions either. All the same, when I see something I want to learn when it comes to drawing, I study and evaluate it then I try to draw it. There's the first trial, second trial, and it goes on and on until I am satisfied. Then, after a few years, I check it and if I recognize some defect, I redraw the whole thing with the way I want it to look like.)biggrinwhee