It's a hard role to keep sustaining and sometimes you can feel that you aren't even sure of who you are. To live without ever getting to be yourself is a frightening fear.
It gets more difficult to be genuine when this is a repeated behavior . Due to continuity, we feel we must keep acting the same way too. For instance, you may go along with office gossip even if you aren't comfortable with it to fit in. When we do things outside of our true nature, we end up feeling divided and split as well as insincere inside. It is hard to live like a ghost or shadow and you are depriving yourself and others of seeing who you really are.
The first thing to assess is why you are putting on the mask and if it's really necessary. People are not looking for identical clones of themselves. It's fine to have a different politcial position, another outlook on child raising or a controversial point of view. Do you like people to be exactly like you or do you like someone with a personality? Would you like someone to be your friend who only accepts people who subscribes to the current trends and is not open-minded?
Try now to take those risks with people who are familiar with you. They may be surprised, but they will also like the aliveness you have. If someone doesn't want you to be yourself, is that a person you really want to associate with? It is scary to come out from under the persona but you will feel a relief and very often a joy at the positive responses you'll get. It is a lot of work trying to be someone else! There is no one like you and your uniqueness should shine through.