Hard to know what is causing your hand pain as it is most likely not from your neck. You could have a compressive neuropathy (See: https://neckandback.com/conditions/nerve-entrapment-compression/)
Your headaches could originate from C4-5 (“.C4-C5: Minimal disc osteophyte just abutting the thecal sac. No disc protrusion or spinal stenosis. Mild mild foraminal narrowing C4-C5 from uncinate spurring”) but much less likely.
You could have facet arthrosis from C2-3 or C3-4 which can cause base of the neck headaches although the radiologist did not comment on degeneration of the facets there. It is not uncommon to overlook that finding. A visit to a well qualified pain doctor could be helpful.
Dr. Corenman