What to do? Need help from you all please read my question?

Let me tell you in short story. I am in relation with this girl from 1.5yrs. Its long distance relationship. well we never had fight. We both are loyal to each other. Trust each other very much. Our parents have no prob in our marriage. Everything was going fine with us. Suddenly from september her life started to change. Main downfall of our relation:-

1. Her sister got divorced. She had love marriage.
2. Her frd told me that her dad has affair with other women.
3. Due to this she cant do good at her office. She told me that I love her with true heart. She used to say she is confused. She wanna make her feelings sure. She didnt contact me in september but she contact my elder sis. She chat her & told she is sacred of marriage. There was one time when she used to plan our future. In november she came back for month. My one cousin asked her WHEN are you COMING HERE. WE ALL are MISSING you SO MUCH. She replied, I DONT NO WHEN BUT I WISH THAT DAY COME SOON. Then my parents send her clothes as gift. She respect my family lot. Now she didnt contact me from 2months. Her whole family no about me. I know no other guy wil love her family so much. What should I do to get her fear of marriage out. Her frd told me that she said she wil reply when everything wil be fine. I dont want to leave her. I am not interested in any other. I can wait for her years. Just what you all think. Wil she come back. The main prob is her family is in trouble. Her parents liked me so much. She hide her dad prob becoz she thought I wil not respect him. But I love them all. She is so true from her heart. I just wanna give her happiness. I am MECHANICAL ENGINEER. So I have good future. please drop your suggestions? She is in trouble.