I am a mistake of a violinist. Going into my freshman year of college, I've been playing the violin since fourth grade. There was a long while where I neglected to practice and just dicked around in class and it's just now biting me in the ass. I want to get serious about playing but I've developed a horrible left hand position, broken vibrato, and several other bad habits; they're a bitch to break. Any other musicians know what I should do to improve myself?