Dear Sis,
What I can understand from your post, You belong to such family where relatives are always ready to find (Moreover create) an issue for Gossips and tamasha. I can understand problem of your father, especially If you have any younger sister (or Including close cousin), Your Inter caste/community marriage will definitely create hurdles in her relations. In your community marriage within caste/community, It is not guaranteed will always be success. But, rate of failure is very low, due to involvement and influence of old family members in family affairs.
One reason your family against this relation might be due to sense of insecurity for you. You are carrying this relation for last four years. Have you earned any additional qualification, So that you can face and convince your family strongly. How good your friend is qualified, How he is earning? Remember success of Inter caste marriage increase if both the partners are at par. Just think with calm mind. Marriage is not a relation between two individuals but also between two families. Even if you manage to marry him anyway, after some years your parents forgive you and adopt, But, in case his family does not treat you fairly, what you will do? What life will be?
I am not trying to confuse you, but to bringing close to truth, as in such condition it becomes very difficult for mind to understand and accept the facts. Be strong, Develop confidence in you. Try to convince first yourself, then to your family. If can’t, Then accept and respect your destiny. Whatsoever will happen in your life, will happen for Good!
May Sai Bless You!
om sri sai ram!