Unintentional weight loss is always a huge concern.
I think you should talk to your doctor again. Whether it is physical or mental (eating disorder) it needs addressing.
Talk to your doctor.
im no expert but i've noticed that the more i exercise the more i get hungery and this maintains my weight. Even when I have alot to worry about in life, I see that excersie makes me hungry. Also resistance training is superhelpful.
if your not eating is there a reason? like depression or worried about something?
Have you been tested for diabetes?
What does your diet consist of? Do you excersise frequently? Are you vegetarian? any of these things could cause this.