I'm just trying to straighten my neck after attempting to view this image at 90 degrees rotation, as Willie suggested.
Yes it does look better. But I often do whatever angle of rotation looks best, not just the 'whole numbers'.
Don't worry about shooting common flies. When you are learning macro photography anything which is prepared to sit still is a valid target! And what you learn will set you up for those rare flies; when you only have a second to get everything correct.
My other comments are, try to get square with the subject; make sure you are focusing on the subject (and showing sharp eyes) auto focus often focuses on the foreground/background instead.
Most macro images will require a little selective sharpening and brightness adjustment.
Above all else, expect a lot of rejects; but keep on shooting.