I have very strict muslim parents?

i have very strict muslim parents and they will not let me have love marraige. my dad already chose a guy for me and i dont love him. i introduced my mom to my boyfriend that i have been dateing for 2 years. he treats me like a princess and has never forced me to do anything . we are deeply in love with eachother and want to get married. we were thinking of running away but i dont want to hurt my dad. my mom said that our marraige can not take place because he is from bangladesh and im from persia. she needs to understand that hes still muslim. i dont know how to convince them. i tried to talk it out but my dad is crazy and i know he wont allow it to happen no matter what . he wants things to only go his way. i know i have seen him act like that towards my brother. thats why he kicked my brother out of the house and declared him dead for the family . now my brother has a child but my deads heart still didnt melt. and i dont want to be the reason for his heart attack once again. HELP ME PLEASE!!!! =[