Superglue and clamp, for sure. That's step one.
Next, round ALL sharp edges. Sharp transitions like what you have in the nocks allow stresses to accumulate and pop splinters. Round the edges and you disperse the stresses.
A thread and superglue wrap around the limb just below the nock wouldn't be out of line, either!
Stick with it, beat this stave into submission....gently of course.