Hi delfam.
Welcome to our Mattress Forum!
The description of your sleep posture and discomfort is a classic example of a too soft of a mattress lacking appropriate support for your needs. Even though you are not able to visually assess your spinal alignment you definitely have enough clues that point to inappropriate spinal alignment. I’d call this more of a blind purchase as you were not able to assess either of the 2 important criteria when purchasing a mattress 1. The quality of the componentry and 2) the level of comfort/support this mattress offers.
Even though an inconvenience the returning this product may be more of a blessing in disguise as you’d have a second chance to make a more informed mattress purchase the second time around. Typically the road to a successful mattress purchase starts with finding the specifics of what is inside any mattress you were considering to assess the quality of the materials (see the article about the Mattress specifications you need to know) which will tell you much about how long you can sleep well on any mattress you consider… a mattress is only as good as the quality of the materials inside.
While you’ve selected the firmer version of the 2 comfort levels BB offers for their Coper Dream line, there is not much meaningful information that will allow you to assess the quality of materials inside the mattress (density) and the IFD that would be a more appropriate way of measuring softness comfort in this case. This is the only information they list on their site which is not enough to make an appropriate selection or whether it has any obvious weak links in terms of durability.
(12") Copper Dreams
1.5" copper-graphite infusion memory foam (density, IFD unknown)
2.5" memory foam (density, IFD unknown)
2" transition foam (density, IFD unknown)
6" HD polyurethane foam core (density, IFD unknown)
As you are experiencing sinking in and misalignment from start, any further “breaking-in” of your new mattress would only exacerbate the issues. So I’d not wait in your case for the recommended 30 days of adjustment period. Typically within a period of around 30 days, the foam will soften gradually and the fabric covering your mattress will stretch out, as well as you adjusting and losing some of your own personal “learned alignment”.
You seem to be in need of more support. This can be achieved by all types of mattresses (from hybrid to all foam) however, in terms of needs and preferences it would be impossible for anyone to say to pinpoint a configuration that works for you as only you can feel what you feel on a mattress. This also involves you having an experiential baseline of some sort, of what worked in the past, with a more detailed description of the comfort/support layers that work for you. You’d also need to collect all the specifics of any new mattress that you are considering which will allow you to make more meaningful comparisons.
It’s much more difficult to firm up the support of a mattress that is too soft (unless you can exchange a layer) because this involves removing or replacing layers or components. So it looks that you’d be better off returning the product(s) and starting anew with a more informed purchase approach. (see suggestions below)
The bedframe is an important part of the sleeping system and is the part that supports everything else (the foundation, the mattress, and the people on the mattress). In the case of a steel bedframe, I would make sure it has at least 1.5" angle iron and good center support to the floor (preferably with at least two legs for king sizes) and legs that don’t bend or collapse when you move the bed. I would avoid the cheapest versions which can be weaker and not as solid or well-constructed. I would look at more heavy-duty frames.
Regardless of the name of the manufacturer, once you determine the minimum level of quality you’d accept in your mattress, then determine the type of materials you prefer in your mattress. Only after this you can start looking into finding if the mattress you are considering is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) …. The mattress shopping tutorial here has the basic information, steps, and guidelines including suggestions about how to test a mattress for what I call PPP (Posture and alignment, Pressure relief, and Personal preferences) that can simplify your search and help you make the best possible choices.
There is some fairly extensive general information in the mattresses section of the site (particularly in the sections about sleeping style, preferences, and statistics along with putting the layers together and the page on tips and tricks here ) that can give you some general concepts, guidelines, and insights about the effects of different body types, sleeping styles, and mattress designs for different people but this is only generic and not specific to any particular person and may be more complex than you really need to know.
It looks like budget is a big consideration so I’d also look at your other parts of your personal value equation
Once you have a chance to read through the information provided, let us know if you have additional questions.
Phoenix