Try 'belly breathing' exercises at home.
Breathe in deeply and slowly through your nose - about 5 seconds
When your lungs are full, hold - about 1-2 seconds
Notice any tension in your body
Exhale slowly through your mouth - about 5 seconds
As you exhale, allow your muscles to relax
When your lungs are empty, hold - about 1-2 seconds
Allow your body to sink into your chair just a bit