How do I tell me my vegan girlfriend that I have stopped eating meat...?

[LeftyMom]

4. I suspect you're overthinking it.

For that matter, if she knows you pretty well she likely had some inkling that your thinking was moving in this direction.

What you might run into is people outside your relationship assuming that you "gave up meat" for her. Guys tend to get that a lot. American culture that tends to associate meat with manliness and regard vegetarian diets as deprivation, so don't be surprised if you get comments to that effect.