How Do I Overcome Fear Of Getting Allergies From Food?

Hello, I m feeling that I am running out of options rather quickly. I am 22, 6ft 1, and weigh about 150lbs. July 2010, I was shot in the head. Since then I have had SEVERE anxiety/panic attacks. All my fears revolve around health/death. Recently, I have developed this overwhelming fear that I m going to have an allergic reaction to something I eat. Two periods of time (about 6-7 days each) I didn t eat ANYTHING. Before these fears of allergies, I weighed about 205lbs. Which was about 3 to 3 1/2 months ago. I have gotten myself to eat a turkey sandwich every day for the past week now though. I have been diagnosed with the panic attacks, PTSD, severe anxiety, and most recently anorexia (I do DESPERATELY want to eat, I am just afraid). Keep in mind, neither of my parents or siblings have any allergies towards any foods. It s just I read on the internet that an allergic reaction can happen at any time, to anyone. And the fear that it COULD happen is preventing me from eating properly. I am currently taking Celexa 20mg once daily for about a month and a half. They want to increase it to 40mg daily, but my overbearing fears of the chance of serotonin syndrome are keeping me from taking the higher dose.