If your arrows were once flying true, no wobble, no wild flight, then let's forget about the "aim small" and 'focus' advice, and concentrate on your form.
First thing to acknowledge is the harder you try, the harder it becomes. This means if you are overdrawing, stretching to get the most, you'll flub the shot. If you are bending your head into the string and canting the bow to 'aim better', your string deflection is going to make for lousy flight, and if you're pressing the string into the face, its a disaster before the release.
I'd recommend that you concentrate on standing erect, holding the bow mostly plumb, drawing naturally, be conscious of the string pressure on the face, be aware of the loading of the pressure on the fingers, and your foot positioning.
Just my 2 cents.