What is your mother's girl name

Change of name to mother's maiden name possible?

The following story about it:

I was born in March 1998. I got my mother's maiden name as my maiden name. So that's also in my birth certificate! In September 1998 my mother had finally married my stepfather (my mother had never married his own). I and my mother have been using my stepfather's surname ever since. Then five years ago they got divorced. I'm 19 now and one thing is for sure: I can identify with my maiden name and, at the same time, the last name of the only part of my family I know more than with my stepfather's. And because of the events that were also stressful for me as a child that ultimately led to the divorce, I would like to be able to put a stop to it for good. The same goes for my mother. But for financial reasons, neither of us could afford to be renamed. Not because of the application, but rather because a number of documents would also have to be newly obtained, for example. However, since I am now doing an apprenticeship, renaming would be at least financially conceivable.

Now my questions:

Is it possible for me to legally rename my maiden name again?

Is renaming still possible for me and my mother even 5 years after the divorce?

If both of these can be answered with yes: How familiar and legally informed are registry offices with such cases? In other words: Do I have to expect to have to fight for my rights? Me and my mother were dependent on welfare for years. We have experience of how well the authorities know or can interpret legal situations * laughs *.