I used to have anxiety in the past, and I noticed at one point that my anxiety was directly influenced to how excited/active the mind was at any particular time.
So, I began to look into ways of getting a hold of my overactive mind, which eventually led me to various meditation practices. What I came to learn over several years or study and practice, is that that the mind and the breathing rhythms of the body and linked.
If your breathing is obstructed and not flowing properly, the mind enters a type of perpetual agitated state, where every little thing/event becomes an irritant or causes anxiety and restlessness.
Control and regulation of the breath is the key to getting control of your anxiety!