RE: What have I done.
Please accept my condolences for you and your family. Losing a parent is not a pleasant experience, as you know.
I was going to suggest injecting epoxy into the known voids via syringe and then clamping the balsa skin to the foam wing for a day or two. I''ve seen friends use this method successfully after the original binder (spray contact cement) lost its grip.
Ed Cregger