I use to concentrate on my breathing when I was feeling that way and note that I was breathing fine, that it just felt like I wasn't. Changing the subject in your mind too, thinking about something you enjoy or a problem you are trying to solve can help a little to distract from the feelings. Maybe talk to your pins-and-needle parts and ask them to give you a break and stop (as you shake them like you would if they'd fallen asleep).

When do you have these feelings; if you are in a stressful situation at that time, acknowledge that instead of trying to "fight" it; say something like, "okay, I might flunk this test but I'm going to do the best I can right now" and give up whatever fear you have. ("All right, all these people might think I'm stupid, but I'm going to say what I have to say" or, "All right this person isn't going to like me want to be my friend/go out with me but I would like to get to know more about them anyway" or, "I would like a hamburger, I'm going to go to the grocery store and buy buns, meat, and cheese and have the biggest, best burger I can make! Maybe I'll get a Vidalia or Texas Sweet onion too.").