FWIW your back looks quite curved in that pic. If your back isn't flat then your whole spine (including your neck) ends up out of alignment which will cause pain.
You'd generally fix that by increasing your reach, so the stuff on Cycling Tips about you needing a longer stem + saddle setback and lower bars relative to your saddle height looks like pretty reasonable advice. You should give it a try, at least.
FWIW your back looks quite curved in that pic. If your back isn't flat then your whole spine (including your neck) ends up out of alignment which will cause pain.
You'd generally fix that by increasing your reach, so the stuff on Cycling Tips about you needing a longer stem + saddle setback and lower bars relative to your saddle height looks like pretty reasonable advice. You should give it a try, at least.