Like the others, I think that there's nothing wrong with being gay, and accepting that part of your life can seriously improve your well being, instead of denying yourself just to fit in.

Now on the issue of coming out, I think you need to carefully consider the possible implications regarding your family. Strictly speaking, they do not have to know, it's your business. If you think that they are so psychologically unprepared that they might react violently, then it's probably best not to do it, specially while you're totally dependent on them. And although I understand Courtney's point of view, she also needs to take into consideration your own circumstances.

I do think that it would be better in the end if your family got to know about that side of your life, but probably not while you're so vulnerable. Maybe it's better to do it when you're an adult, financially independent, and able to prove to your parents that you can lead your life on your own terms. Also do consider that once you start leaking that kind of information, you cannot control it anymore. After all, if you could not keep it for yourself, why would others do it? On the other hand, perhaps your sister might be of some support to you, but you do need to be cautious about it. My feeling is that when faced with an hostile background (such as a very conservative anti-gay culture), it's better to grow up and gain some life experience before tackling those issues with your family. This does not mean that you should not go out with Courtney, quite the contrary (you can't grow up if you stifle yourself). Just be cautious and use common sense to avoid potential trouble.