Postpartum eating disorder.

I’m a teen mom(18), and I had my daughter early this year. I’ve struggled with postpartum depression but I’ve been getting a lot better recently. Or so I thought. I think I have an eating disorder. I don’t want to go into too much detail. But basically I’ve lost about 15 pounds in a month and I just can’t eat. I try so hard but I can’t. My body won’t let me. I know i need to go to a doctor but I’m terrified they’re gonna label me unfit and take my daughter from me. When I was about 13 I struggled with severe mental health issues and i had an eating disorder but I got help for it and recovered after spending some time in a mental hospital. I’m scared that they’re gonna look at my current situation, look at my issues from years ago, and decided to take her from me. That’s the only thing stopping me from getting help. I don’t want to lose her. Someone please tell what I should do