You might be overbowed. The general form is to come to predraw with your string hand at about mouth/nose level and draw back to anchor (or, under the jaw an inch or two and then up to anchor for FITA). If you find that you have to draw at chest level (and possibly arching your back) in order to get back, I'd suggest lowering draw weight. You're going to maximize form and performance with lower draw weight I think. Do you have a video of you shooting available?