I read your post and had to reply. I totally get the idea of having to make face for others. The question becomes why do people feel the need to do this and there are reasons, though often we dont recognize them. Though you may not appear sad, the build up of trying to be something for others wears you down and does become saddening after awhile.
Imagine if you found out you were meant to be a famous dancer, but that never came to be because others couldnt see it, but it was in you, and you never realized that dream. That would be saddening. There is a really cool person inside of you, and this situation might be telling you, they want you to come out. You dont want to live your life for others, otherwise you give your life away, and your life is for you; not them. You need support to feel strong enough to act on this. This is your life.
What to do first? the first think is to talk to people you feel supported by and here is a great start but there other other steps as well. A doctor maybe, or good friend that understands you, and sometimes even strangers that have no judgements about you. This is your time to be you, not some other person for them. This transition will be a good thing for you in the end; you just need support to follow through with starting to be you.
We are listening.