doing the same simple a bunch of times will allow you to progress. you subconciously change small things, making letters flow better and better over time. it also helps you gain an eye for proportions. so keep drawing the same simple letters. put them together. etc etc. over and over. graffiti is based off of that. don't whine either or say it's boring because that is just proof you should not even start painting.
ruck; you've progressed a lot but still, stick to the books. don't paint yet. if you do though, don't do street shit just practice at a middle of nowhere wall.