First off, I’m really sorry to hear how long you’ve been dealing with this. Poor sleep over an extended period can absolutely affect both physical and mental well-being, and when your body is constantly fighting improper support night after night, it can become incredibly frustrating and discouraging.
From what you described, it actually sounds less like you need an ultra-soft mattress and more like you need a sleep surface that can maintain proper alignment specifically under your hips without creating pressure or tension elsewhere. Since you are a back sleeper with most of your weight concentrated through a narrower hip area, you are essentially creating a concentrated “anchor point” in the center of the mattress. Many conventional foam mattresses — especially softer memory foams and lower-density materials — will gradually allow that area to settle more deeply over time, which then causes the hammocking effect you mentioned.
One thing that stands out to me is that you experienced some improvement on the shikibuton before the cotton compressed. That suggests your body may actually respond better to a flatter, firmer, more stable support surface underneath, with only a modest amount of surface cushioning on top.
Latex may indeed be worth considering for you because it behaves very differently from cotton, memory foam, or conventional polyfoam. Latex is much more resilient and “pushes back” against weight instead of allowing the heavier parts of the body to continually sink deeper over time. It is one of the few materials that can simultaneously provide support and contouring without easily developing body impressions.
As for your question about stacking latex toppers instead of buying a full mattress — no, that is not naive at all. In fact, many all-latex mattresses are essentially individual latex layers stacked inside a zippered cover. Functionally, that is very similar. The important part is choosing the correct firmness levels and total thickness so the layers work together properly.
Given your build and sleeping style, I would personally lean away from very thick soft comfort layers. I suspect you may do better with:
- A firmer support layer underneath to prevent your hips from sinking excessively
- A thinner softer comfort layer on top for pressure relief through your upper back and shoulders
- A flatter, more level overall sleeping posture
You may even benefit from a setup that feels “firmer than expected” initially but keeps your spine in a more neutral position throughout the night.
Another thing worth mentioning: your foundation or base matters tremendously with latex. Because latex conforms closely to whatever is underneath it, even a slightly flexing or uneven foundation can contribute to the kind of hammocking you’re describing.
I also want to gently mention that while a mattress can absolutely contribute to pain, fatigue, inflammation, and poor recovery, persistent or worsening symptoms — especially after a medical scare — deserve continued attention from a healthcare professional as well. Sometimes sleep posture and physical issues feed into each other in a cycle, and addressing both together tends to lead to the best outcomes.
You are not crazy for continuing to search for answers here. Sleep systems are highly individual, and based on your description, your body may simply be more sensitive to alignment changes than most people’s.
I hope some of this helps point you in a better direction.