Missing girlfriend and family

Sir My college girlfriend and I were madly in love with each other, we both wanted to marry each other, so may of 2012 at the end of our college term she left with her family to USA to visit her sister, for 3 months, she took a transit flight from Sri Lanka, her last mail was from Sri Lanka...after that I have been waiting for her mail and did not get one until 3 months later her elder sister sent a mail through my girls mail that " she has revealed about you to our parents and my parents are in shock, they are against inter caste relations...it's very difficult to make things work here" after this I was very depressed and I was waiting to confront them when they comeback....I waited for six months and there was no sign of them...one year later their house was demolished and they have contracted it to some builders...they have shifted...when I asked the care taker he said that mother is in Bangalore living with her other daughter and father is in Sri Lanka for business....I am really depressed and it's very hard living without any info about her....without closure I will never be able to move on....she promised me marriage and met my mother and she said doesn't matter how many ever years it takes I will convince my parents and come back....now I am really worried...please advice.she is a Sikh and I am Hindu.