Thing I will leave you with wayne... When you see somebody who is fast and just looks right on a road bike, there is very little chance to it. Trial and error and a lot of hard work to dial the fit. I personally over many years have gone through countless fittings and experimentation and to this day, I still tweak my set up. 1 degree of saddle tilt...even changing the handlebar..ergonomics vary...position of the shifters...a spacer here or there...small changes can make a big difference. Also a camera doesn't lie. Get a trainer and take pictures of your position if you need more feedback.
Neck pain is perhaps the no.1 issue with a road bike for the simple reason that you are trying to cheat wind the best you can to maximize your speed. A very common newbie mistake and I still work on this decades later is proper pelvis rotation. A simple 'commitment' to proper position of the pelvis on the bike makes a road bike so much easier to ride in an aero position. Rotating your pelvis allows you to maintain good posture without high back flexion or a hump back which makes neck extension much more difficult which leads to neck pain. Satisfactory reach promotes better posture. Its hard to ride a short cockpit road bike properly with good posture. If you have to reach a bit more for your bars, you will be more inclined to rotate your pelvis properly forward.
See below.