Hi mowgli,
I’m sorry your Outrageous mattress isn’t working out for you as well as you had liked. 
Without seeing the mattress and knowing the exact specifications of what is inside (details that you stated you weren’t as interested in when you made your original purchase), I’m sorry I can’t comment too much on what might not be working so well for you. But if I had to guess, it would be the polyfoam in the quilt on top that may not have been a match for you at your higher BMI.
Post #3 here has more information and suggestions about heavier weights that would be worth reading down the road as you approach your next mattress purchase.
Thanks for your update.
Phoenix