Go to the shop where the guy has been to the
Ebonite training, Jeff Userey runs it and is one of the best drillers in bowling. I would feel confident in anyone that has been trained by him or the staff at
Ebonite.
Your span is way too long. Who ever drilled that doesn't know what he/she is doing. You can tell if your span is correct by placing your thumb in the ball and laying your fingers across the holes. The leading edge (side closest to the thumb) of the finger hole should be no longer than half way between the first and second knuckle of the middle and ring finger without stretching your hand, it should be relaxed. It can be a little shorter than that, but not shorter than one quarter from the second knuckle.
If you already have a ball you can tell if your span is right by putting your hand in the ball and see if the fingernails are pressing the back of the holes, a properly fit ball will not have the fingers pressing into the back of the hole.
On my balls I can put my thumb in first and still be able to put my fingers in the ball, I don’t advocate doing this, but it is a good test to see if your span is too long.
Your thumb hole is way too big, I can see 1/2 of the hole with your thumb in it. This usually happens because you are bending the knuckle to hang onto the ball. If you put your thumb in the ball, it should be fairly tight with your thumb straight (it can be a touch lose to allow for
tape/magic carpet).
At 4" span you should be at 1/4" forward to start out with, then keep going forward until your thumb catches slightly, then back off 1/16". I recommend going forward 1/4" at a time to save on drillings. Just make sure it is not you squeezing the ball before you give up on a thumb pitch and back off. Once you get the feel of allowing your thumb to relax in the hole you will be able to tell when you squeeze the ball or not.
Word of warning, you will throw the ball through the ceiling if you go to forward pitch and still bend the thumb, so let the ball fall off your hand or you will risk injuring yourself.