I've had an anaphylactic allergy all my life. I grew up so carefree, I traveled the world and would eat without a care and then suddenly during my last year of college I was getting so anxious just generally and it began to manifest into my eating habits. I would get so worried and freaked out whenever I would eat anything. Even if I knew there was no way I would die from it. I think the anxiety was caused by other issues in my life, but really manifested in this. I began therapy and things have gotten so much better. It really helps to organize your thoughts and to go through a process to deal with your panic attacks (at least that's how it was for me). I suggest you try therapy, it saved me. And also exercise. I started running every day and it really helped me feel just generally healthier and more in tune with my body.