Hi Katia,
Thanks for the update.
As you know from my previous replies you really haven’t slept on your mattress for long enough to be able to reliably assess whether you need to make any changes yet or if you do the types of changes that may be most helpful but I can link you to some of the additional information that I mentioned in my previous post.
There is more detailed information about the most common symptoms that people may experience when they sleep on a mattress and the most likely (although not the only) reasons for them in post #2 here.
There is more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel”.
These posts are the “tools” that can help with the analysis, detective work, or trial and error that may be necessary to help you learn your body’s language and “translate” what your body is trying to tell you so you can make the types of changes or additions to your mattress that have the best chance of reducing or eliminating any “symptoms” you are experiencing out of the options that are available to you.
There are also some suggestions in post #2 here that may also be helpful if your mattress is too firm.
Phoenix