The ball has been drilled for my hand and fits perfectly. When I insert my thumb all the way in the ball, it makes my back swing easier but I can't seem to get the right rotation on the ball and it doesn't hook.
There is more to the game than rotation, just getting rotation on the ball with no direction is not as good as no rotation and hitting your target. Sounds like you are trying to learn to run before you can walk, you might want to take a step back and take some lessons and do some exercises to strengthen your wrist.
If I try hard to really lift the ball with my fingertips to put rotation on it, it really strains and hurts my wrist.
Pain is an indication that your ball doesn't fit your hand properly, or is too heavy. Usually pain like this means your span is too long.
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 equipment, I can put my thumb in first and still be able to put my fingers in the ball, I donít advocate bowling like this, but it is a good test to see if your span is too long.