Really concentrate on staying in the moment, don't let the anxiety in. Big breaths and think of somewhere pleasant in your mind. The mind is a funny thing as it can only concentrate on one think at a time. Let the anxious throught enter and then let it exit right out.
You do not need it in your head. Remember you have anxiety, it does not have you.
Gentle Hugs and know we all care here for you. Keep working at controlling those thoughts.