Hi matwhich,
There is more about the break in and adjustment period in post #3 here. It can vary from person to person but it would normally be about a month or less … and sometimes much less for some people.
There are also some suggestions in post #2 here that may be helpful. I don’t know what type of mattress protector or mattress pad you have but it’s also possible that it could be interfering with the ability of the foam layers to contour to the shape of your body which could be firming up your mattress as well which could also affect alignment/support.
Phoenix