All I can keep saying is I JUST DONT GET IT....

And there are trans people that just don't get what it feels like to identify as the gender they were assigned at birth. They have no idea what your life feels like. And that's fine. Everyone is different, and just because you can't imagine what it might be like to identify as a different gender doesn't mean that people out there don't go through that. There's lots of science about gender dysphoria. People aren't just making it up. There was a time when your first sentences about being gay would have been considered absolutely radical. Just like the fact that there were always gay people and we've just come to accept them, there were always trans people, and they are currently fighting for the same acceptance.