Why not go see your doctor about this? He/she can help you determine what is wrong, and can rule out causes and maybe even refer you to a counselor that can help with your anxiety. As mammo said, you don't have to be experiencing a full blown panic attack to notice the symptoms of anxiety. Keep us posted!
Because of your symptoms it could be your blood sugar getting too low, but I'm not a doctor. My husband who is diabetic experiences this when his blood sugar gets too low. I experienced this and it was anxiety, but my doctor said if eating something didn't make me feel better right away, it wasn't my blood sugar. I was tested and it wasn't my sugar, but anxiety. Always rule out other problems before assuming anything, but you also describe what a panic attack can be like and your eating may be comforting to you, gets your mind off of what is happening and it passes. You don't have to always feel nervous or anxious to have a panic attack. See your doctor to rule out sugar problems, and go from there. We're always here, so please visit us anytime should this turn out to be anxiety. Take care.