I'm pretty sure your music teachers have told you this, but you need to practice consistently, everyday, which is most likely the problem. I know practicing is not the most exciting thing in the world, especially when you're a beginner, but practice is why Jimi Hendrix is a guitar god, and why Neil Peart is a crazy ass drummer. These guys literally devoted every free second of their lives to practicing. Hendrix literally fell asleep with his guitar on top of him very frequently when he was a kid.
You could learn something from him.
Music should be an art from the heart, not something for the mart.
Music is like Chinese food; the longer it sticks around, the more interesting it gets.