Matt's picture shows a perfect example of what I was talking about. You can draw a straight vertical line from his iris to the nock, all the way down to his belt buckle. His back elbow is actually a little high, but he is an experienced archer and can get away with that without having adverse affects. The main thing is the back arm is straight from elbow to anchor. Look at his bow arm as well. It looks solid and stable. This is what you want. If you straighten up you should be able to achieve this. Take it all one step at a time as Matt said.