I'm not going to tell my girlfriend that I'm transgender.
Does it make you afraid to think of how she may react.
Yea. I am not exactly sure how she is going to feel about it. I'm pretty scared to tell her.
If she finds out on her own she will be mad too. So it just makes sense to tell her as soon as possible. If she truly loves you then she will accept you for who you are.
I'm not sure how she will react but I don't want to lose her.
Its understandable to be afraid of how she will act. But this way when you tell her you will find out for sure if she deep down truly has feelings for you enough to stay with you no matter what. That is the best love you could get. Secrets just convey dishonesty otherwise.