I had massive issues like these in the past until I spoke with a person who provides therapy for these specific problems. The first day, he gave me a book on the topic and said that it had valuable info up to about chapter 4. In a nutshell, and from that book, who's title eludes me, I created the FU technique. I know, it sounds ridiculous but it totally works for me. Aside from diet leading to your issues, the best solution for dealing with panic / anxiety is to get angry with yourself. I have stopped numerous panic attacks talking trash to myself. Once you get used to its effect, move on to imbibing in physical activities that also induce panic / anxiety. This will help you build a permanent foundation of self trust and accomplishment. Like killing it on your assignments. Another thing is to learn to crave the anxiety associated with these tasks. Try to teach yourself to get excited with each new challenge. The more you engage in things that make you uneasy and succeed, the more you can handle.