No Title, Just Confusion

So, before I identified as trans (I came out two years ago when I was away from home and felt safer) I identified as a gold star lesbian. I’ve never once been with a guy, and I’ve never before felt attracted to a guy. But now, I’ve been with my girlfriend for almost two years, and a couple months ago I noticed something. I might like guys now? Like, a very strong maybe? And I know it’s not a bad thing, I’m just confused. How do I tell my girlfriend without her leaving me?