Anxiety , anger and family issues.

I am 27 yrs old . I am myself a MBBS graduate and presently still studying. But going through a bad phase of life . I get angry very soon . I don't know how to control myself , how to be calm . And this happens only with my family members . I get angry on them even for a very small reason. And since I have stayed away from home for more than 10yrs now due to studies .. I have become very broad minded . But everyone in my family is very conservative. So I frequently get into arguments at home . And i have too much pressure to get married to the guy of their choice but I am already in a relationship with another guy since 7yrs  which they are not ready to accept. This adds on to more arguments. I really don't know how to handle this and it ends up in an argument . I am emotionally very weak and end up crying . I want to control my emotions . I want to change myself. Plz suggest me something . Thank u.