Hi passiim,
Thanks for the update and I’m sorry to hear about some of your more negative experiences with the topper and the foundation.
The normal adjustment period would be in the range from just a few days for some people and up to about 90 days for some others but it would typically be in the range of a few weeks depending on how different your mattress is from what you are used to sleeping on. There is more about the adjustment period in post #3 here. If you are still experiencing back pain after 30 days then it’s more likely that the mattress isn’t the most suitable “match” for you in terms of PPP and you may need to make some adjustments.
Post #2 here has more information about the most common symptoms that people may experience on a mattress and some of the most likely reasons that can cause them.
If you are experiencing lower back pain … then the most common (but not the only) reason would be comfort layers that are too thick and/or soft which are “allowing” your hips/pelvis to sink down too far before they are “stopped” by the firmer transition and support layers and are putting you out of your neutral alignment range for too long over the course of the night.
There is more about the smell of latex in post #2 here. Talalay latex generally has a somewhat sweet smell but the strength of the smell can vary from batch to batch. For most people it’s not an issue (and some actually like it) and the smell dissipates to levels that they don’t notice in a few weeks but some people are more sensitive than others and some batches may have a stronger smell than others so in some cases it may take a little longer. There is also more information in post #3 here that may help as well.
If your topper was soiled I probably would have asked them to replace it when I received it but it’s quite possible that 3" of 14 ILD Talalay latex is too thick/soft for you on top of that specific mattress and if I was in your shoes I would first consider trying to sleep on just the mattress without the topper to see if this helps with your back pain. If you notice improvement but you need some additional softness or pressure relief in addition to the mattress by itself then you can add a different topper that may be a more suitable thickness and firmness using the information in post #2 here and the topper guidelines and sources that it links to.
Phoenix