How do i become a calmer person?

Well your doing the right thing by seeing a counselor. A big thing with trying to change yourself is the constant reminding of yourself of what your doing and how it is wrong. When you start to get angry remove yourself from the situation. Simply walk away until your calm. When you are calm think about what made you angry, figure out why you were responding negatively then find a positive solution for the issue. You must also answer the question as to why your getting angry and why its at loved ones and not normal status friends and strangers. That counselor and other forms of pro help are going to help a ton so make sure you listen to them.