Dear friend, I can understand the pain your going through. I can imagine how hard it could be for someone like you that feels terrible losing her to someone. You need help from someone who can understand your pain and help you out in this regard. You can contact a counselor /psychotherapist /couples therapist or relationship counselor who's trained to render help in such areas. A psychiatrist may not be able to do much as you do not have a psychiatric illness but a painful emotional experience that all of us come across.

Hello buddy,  did u share this with your parents? !! If it is not possible at least talk to some of your friends.  If it is still not helping you please consult a counsellor and learn better ideas to come out of this situation at the earliest

Hello There. I can understand your concern. we cannot do much in this regards dear friend. you need to talk to her or just let her go, there are plenty of fish in the sea. you need to let her go really. if it still doesn't help you, kindly consult a psychiatrist for counselling. Best regards, Dr. Anil kumar jain. Bangalore.