How did you tell your friends family and significant others about being an FA?

My girlfriend and I met when we she was a freshman in college. At that time she was pretty skinny and what most would consider traditionally attractive. I knew I was an FA but her personality drew me to her so much that I put that aside and decided to ask her out anyway. Now she’s a junior in college and we’ve been together about 2 and a half years. She’s definitely gained some relationship weight and I obviously find her more attractive than ever but I don’t know how to bring this up to her. I’m torn because if I tell her it’s possible that she freaks out and leaves me but if I don’t tell her then I feel like I’m hiding a part of me from her forever. I feel like if I told her it could help her with her confidence. She has days where she still has all the confidence of her prior skinny self but every once in a while she does have days where she lacks confidence. I’m not sure if telling her would help with that but part of me wants to try I just don’t know how.