Hi and welcome to de-lurkification! I get "Fade Into You" every time I see your username, haha. I think if a doctor diagnosed you with atypical anorexia and expressed concern, that it's worth it to listen to them and maybe at least try to keep an open mind about the situation. I think your BMI is absolutely fine, but if you have disordered eating it's important to work hard to fix that so you can healthily lose those couple pounds, and then maintain your weight by eating to care for your body, not to punish it for the things you don't like about it. I think ultimately it's worth listening to a trained medical professional and their knowledge, over the opinions of a bunch of us strangers. But from one shitlady to another, I think you're cute as hell and I want you to be healthy and happy- which might mean fixing disordered eating/thinking while also maintaining a BMI of ~19, which is completely possible since I maintain the same BMI, love food, and eat well and often! :)