I have found with many of my girls who have been afraid of flyaways that a visual clue is tremendously helpful. Most often, they are afraid of hitting the bar, so I tell them to let go when they can see their toes. That's a little early for a good, high flyaway, but very useful for when you are first learning it. It gives you enough time to flip, but also pulls you away from the bar. I know that you said that you have been doing good flatbacks into the pit, but now when you do them, think about seeing your toes. After you let go, pull your knees over your head. I don't know what you're thinking about, but make sure you think: look for toes; let go; flip. Think it in that order just before each part is about to happen. Once you get used to it, you won't need to think those things, but for now, use it to get you going and get your confidence up. Also, there is a neat drill on YouTube for flyaways. If I can find it, I'll post it. Basically, you do a flatback onto a mat that is leaning against a wall and backroll down it. Try not to get frustrated or let the fear control you. You'll get it!