Terrorist convert?

The other day I called my father which i Havent seen in over a year. He asked me how i was and stuff. i recently told my sister i hav converted ,she was cool about it  and had told my father. After the phone call he call me up like 2 seconds after screaming why ave you turned converted to a muslim, have you become a terrorist. i had to put the phone down cos it mad me so angry and upset. it  made me angry that an well educated man  my own father could come out with such a silly thought that people only convert to Islam to become terrorists. Thats the sort of thinking that would come froma common loser with no understanding of anything. Now the next step is to tell my mum. she was born muslim but was raised as a christian when her muslim mother died. im to scared if she will take the news in the same way as my dad.