Iif you're going to be starting a course of Tai Chi that you first talk to your doctor or physician to see if there are any underlying health reasons why you shouldn't attempt it, as a certain dexterity is required from you to perform some of the movements.
Learning Tai Chi is simple and can be calming especially if incorporated into your daily routine. Once you get the hang of it you'll be able to do it first thing in the morning bringing balance to your whole day. And the breathing techniques learnt along with it might even come to your aid naturally if you do get an anxiety or panic attack.
Simply, Tai Chi is a series of controlled movements that helps to bring the forces of Yin and Yang within you back into a state of balanced control. The high levels of concentration needed to perform these movements properly will take you into a natural state of meditation. This coupled with the steady regular breathing that's required for this is a natural way to calm and soothe you and bring balance back into your life.