Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned by anorexia nervosa and the need for an NG tube for feeding.
Anorexia nervosa is an eating disorder with plethora of complications for the patient. The distorted body image makes the person obsessed with body weight. The proper multidisciplinary approach can help you with the problem including zinc and essential fatty acid supplementation and nutrition counseling. Olanzapine has some role in decreasing obsessionality and other aspects of AN. CBT and family therapy have been known to help. Once you get the benefit from treatment,these symptoms improve and you will start eating on your own and need for NG tube will be taken care of. You must stay in consultation with your team including a psychiatrist for definitive management as the same is not possible online.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.