How close to your body is your left arm? Don't do the chicken wing, it's a cause of pain. Allow the right side of guitar to sit on your leg, allow the neck to come outward so that you're holding your left arm in a natural position. When you're fretting, pay attention that you do NOT bend your wrist at a sharp angle. If you need to move up, try moving your hand forward to give your fingers more upward reach, and if needed, angle the elbow down just a bit more for that angle to keep your forearm and back of your hand as straight as possible. When moving up-down the neck, let your shoulder do the work and keep your forearm and wrist as stable and straight as possible. I hope that helps.