I just started a machine quilting series to learn the finer points of FMQ. We are using the Machine Quilting Made Easy book to follow along.
http://www.amazon.com/Machine-Quilti.../dp/1564770745
OMG - what a difference a class makes. Even the tips for basic straight stitching were wow-worthy. Maybe it would help you too. Don't give up. You may just need to practice a different way.