Keep in mind you have to be very careful when you shim the ring. The contact surface between the rings and the scope tube changes.. (smaller and angled). Then, if you "overtighten" the rings screws, you may (easily) damage the tube.
That said, I would restart from the very beginning. You should center the scope adjustments (mirror method or counting clicks and leaving in the middle). Then, guess the shims you think it would be needed to compensate the droop, mount the scope and shoot 3 rounds, let's say at 10 yards. If you had a 'decent' group, how far is it from the point of aim? If didn't group, you have a problem to find out..
Let's say the group is 'ok', but just out of place. Without turrets adjustments, try to manage the shims until you have, at least, the group no more than 1" out (closer is always better). Only then try to zero with the scope adjustments.
Hope this help.