Yep--what they said--probably a bit too much draw weight, and a bit more shooting that your fingers are used to.

On the anchor point, try establishing a 2 point or 3 point anchor--this really helped me with consistency. My first finger is on a tooth (directly underneath my eye), middle finger basically in the corner of my mouth, and thumb under my jaw, laid straight and pressed against my face. With one anchor point, you still have room to move your hand around a good bit. With three, if you do it right, you can't move it around at all.

Chad