Hi my name is layla and I've been struggling with anorexia for over a year

my bmi last time I was weighed is 17 which is not even that low

I'm currently eating ~1800-2000 calories a day and gaining like crazy/bloating/experiencing all the uncomfortable symptoms

I'm scared to up my calorie intake to 2500-3000 calories because if I'm already gaining on like 1800 calories wouldn't I become fat if I ate 3000 calories? I'm afraid I'm going to gain weight too fast and overshoot on 3000 calories because my bmi isn't that low
and I've noticed that the people who eat 3000 calories are way more underweight than me

how many calories do I really need? is there anyone who was in the same boat as me and wasn't even that underweight but went full on to 2500 calories?

thanks xx