Hi Thedakk.
Welcome to our Mattress Forum. 
There is some information about the many different symptoms that people may experience on a mattress and some of the most common causes behind them in post #2 here that may be helpful.
You’d also want to revaluate the thickness of your pillow to make sure that it is allowing for a more “neutral” neck alignment. Have all the fills been relatively similar in terms of loft?
NikkiTMU