I'm completely self taught as well, and have been shooting for just under 4 years now. In my opinion if you want to get better, you have to be passionate about it, become a little (or a lot) obsessed, you have to try new things and you have to have BIG dreams. Like any art form, you can teach yourself because art is about personal expression. From the looks of it, you have a lot of the technical stuff down, but just need to make improvements that will come with time and practice, NOT WITH AN OVER PRICED SCHOOL LOAN. The only thing stopping you is doubt. Just keep shooting, and focus on improving. The more you shoot, the more you will learn and the better you will become. Just don;t expect it to happen overnight. Like anything worthwhile it takes time and effort.