Welcome to HCM
We understand your concerns
I went through your description. Why worry too much when the problem you are mentioning is not a problem at all. Belly button depth increases simply because you are having a larger tummy than earlier. Nothing else. When you become obese
, fat deposit increases around your belly button and it seems to be in a pit.
Exercise, reduce your tummy. Then it will be alright.
Hope this clears your doubts. Available for further clarifications.