Hi Jae,
Sherwood makes some higher quality/value mattress compared to most major brands (and of course value is also relative to the price at the retailer you purchase from) but I don’t know the specific details of the layers that are in the Cadence so it’s difficult to make any comments about the mattress itself.
A new mattress is usually a little firmer than a floor model and will usually go through an initial softening or “break in” stage over the first 90 days or so. It can also take some time to adjust to the feel of a new sleeping system that is different from what you are used to.
I’m not sure what you mean by feeling a little “rough” though. Do you mean you are feeling the texture of the cover?
If this is the case … a mattress protector or mattress pad that is a little thicker and softer may be a solution. If it really is too firm for you then a topper can also be a way to fine tune your mattress and customize it to your preferences (a mattress that is too firm is much easier to “fix” than a mattress that is too soft). A wool topper can also be a good choice for fibromyalgia.
If you are considering a refund and starting over again … then the better options I’m aware of in the greater Los Angeles area are in post #2 here. There are also a couple of other local mattress manufacturers that are in the Culver city / Santa Monica area that I recently “discovered” in post #6 and #8 here.
In terms of suggestions you are probably more aware than I am of the types of mattresses that you prefer (both soft and supportive) but I think that a latex comfort layer can make a very good choice because of it’s ability to combine softness/pressure relief and support. Being lighter and more sensitive because of your fibromyalgia … you most likely prefer a softer than average comfort layer as well. One of the keys will be the thickness of the layer because if your soft layer is too thick before you reach the support layers then you will sink down further and won’t feel as well supported. Part of the problem may also be the memory foam in your mattress which may not be reacting the same in your bedroom as it did in the showroom (it’s temperature sensitive).
Because of your lighter weight … very soft latex may work well for you and if you want to test softer latex … Pure Latex Bliss has a line of mattresses that use various layers of 19 ILD (plush which is one step below soft) latex on top and they also have a 2" and 3" 14-15 ILD (super plush) talalay latex topper which is as soft as Talalay latex goes and may be worth testing in combination with various mattresses to see how the softest latex works for you. While these may not always be the best value available to you in terms of cost … they can provide a guideline for firmness levels and layering that you could use when working with some of the better value manufacturers in the area.
Phoenix