The one question that I heard from so many people looking for an interior designer or decorator, is that they are afraid to hire a designer because they are afraid that a designer will take over their home and they won't know how to tell them no. I have one very simple answer, simply tell them how you feel.
If you feel a designer or decorator is taking over your home, and it no longer says "you", simply tell them that you feel they are not considering your needs and desires, and that your home no longer has your personality in it. A good designer will take this into account and adjust their approach. A not-so-good designer may not take this into account, in which case, feel free to fire them. Seriously- it may seem harsh, but there are plenty of other designers and decorators in the world, and your area that you can connect with.
Working with a designer is like being in a relationship, when it's working, its great, but when it's not working, it's time to just cut the ties and let them go. So be sure to check in with yourself, and ask if the relationship you have with your designer or decorator is good for you. Becuase at the end of the day, YOU are the one who will have to live in your home, the designer simply gets to walk away from the project and move onto the next.