We dated for 5 years and I thought we would get married. We had planned our entire future together. But yesterday a one line message came on LINE. Want to break up sorry. No explanation no reason. Just one sentence. Called but no answer. Sent messages but no reply. 5 years together ended with one line of text. Did not even have the courage to say it face to face. Cried all night. Do not understand what I did wrong. Everything was normal until yesterday. Friends say there might be someone else. If that is true my heart is shattered.