My girlfriend came out to me as Trans

So I recently started dating a girl i’ve know since high school. She joined the army right out of high school and we grew apart. Recently we reconnected and started dating. I have met her family and she met mine. Then last week she came out to me as identifying as a male. Since then i’ve been calling him the correct pronouns and by the name he identifies with. I just was hoping for advice to see if anyone else has gone through something similar. I love him with all my heart and doesn’t change any of my feelings. I just don’t know how to bring up touchy subjects yet and I was hoping for advice. Thank you!