You need to get it checked out. Given your history, the MVA aggrevated pre-existing problems. Hopefully, all you need is some physical therapy on the neck. It's better safe than sorry!

I was in an MVA 6 years ago that seemed like nothing at first. I refused treatment at the scene but by the next morning, the pain set in. I didn't seek treatment until a few days went by because I thought I could handle it and it would just go away. As a result, I have problems at C2 and C5/C6 from this car accident and ended up with a couple of surgeries due to the MVA (none on the spine yet but likely down the road).

Hopefully, it's just whiplash and tight muscles causing the problems.