Hi briang,
There really isn’t much I can add to MattressToGo’s comments and suggestions and the comments from the other members that have replied to you.
There is also more about the most common symptoms that people may experience on a mattress and the most likely reasons for them in post #2 here that may be helpful as well.
While I don’t have any specific reference points about your body type or mattresses that you have slept well on and how they compare to your mattress … the most common (although not the only) reason for lower back issues are comfort layers that are too thick/soft and/or a support core that is too soft.
If your mattress is too soft there are also some suggestions in post #4 here that may be helpful as well.
Phoenix