dont use arrows. start off with just simple letters. uhhh choose a single vanish point and stick with it, it seems like all the 3d drops of your letters are going in different directions. and keep all the letters in uniform lengths and widths.
Alex, is this your first sketch?
Anyways, try starting the sketch with just simple basic letters and add the extra stuff later on. And practice alot, haha. Don't draw too much in school though, I used to draw all the time in classes and didn't really care about the things I was supposed to learn in class.. I kinda regret it now haha