I was so uncomfortable last night that I was dreaming about the mattress 
Got up an hour early, completely discouraged that I’m experiencing lower back pain that’s actually worse than on the old mattress. I’m baffled at this point because eventhough the 6" core is 40 ILD, I still feel like my hips are sinking/my waist is sunken into the mattress. ??
Today I’m going to buy a convoluted foam topper - hoping the lower back issue is too much firmness
Tonight we put the mattress directly on the floor to see if that makes any difference.
I read that post by needanewmattress:https://forum.mattressunderground.com/t/too-many-bad-beds-from-waterbed-to-latex-to-memory-foam-to-airbed-bad-lower-back-pain It also mirrors my issue and it scared the heck out of me.