Panic Attacks: Relax. If you are experiencing a panic attack, sit down in a safe place and focus on deep breathing slowly and regularly. Try just that for a few minutes. Consider a combination of treatments if you experience them often: medications such as ssris (avoid benzodiazepines except for emergency situations), learn relaxation techniques, ejercise daily, sleep well and avoid alcohol and caffeine.
Therapy and skills. You can learn coping skills such as deep breathing, relaxation, etc. However, i recommend you also take the time to understand what causes you anxiety/panic. Psychotherapy can be very helpful for this. Your therapist can teach you several ways of controlling your anxiety and panic attacks while also getting to the root of your anxieties. This would likely make for a long-term solution to your anx.