Hi there, sorry to hear about your accident. Whiplash is NO fun!! Yes, there definitely can be a coorelations btw. the sensation you are feeling and your accident. Like your posterior neck, your anterior (front) neck also has muscles (the longus colli and capitis to be specific). These muscles can develop trigger points in them that can recreate the sensation. It definitely would not hurt to find a good massage therapist familiar w/anterior neck work in your area to help.
As far as i know it might not be the case, to ease that acid reflux you can try taking a glass of spinach and ginger juice in the morning. It helps a lot, I would suggest you to have a look at healandhealth to know on how to remove acidity from the stomach.