This question is for people who have food allergies?

Okay yesterday night around 6pm I was going to eat a snickers chocolate bar and well at the same time I said what if I had become suddennly allergic to it and die I was joking though. But I was like oh whatever and ate it. And about 20 mins later I started to feel my neck tense but with no other symptom and then I started to panic about it and symptoms got worse. 30 mins later I would get a panic attack TOO I have anxiety problem. Minutes after my attack not only did I have my neck tight but I had trouble breathing. So I went to my mom and told her what if it's allergies to the chocolate I ate or peanuts that it had. She said it can't be cause my face would have swollen up and my neck or even my tounge, basically anywhere the peanut or chocolate touched. So I went to sleep and I woke up with the same symptom with my throat tight. and it's kind of difficult to swallow. Is this allergy? I been like this for more than 13 hours something more worse would have happened right if it was allergy right? Can someone help me out and if it is allergy would Claritin do?