I said I love you and her boyfriend said to kill me with the gun

Actually I said I Love You To A Girl Who Is My Crush. I said only I love you to her and nothing harrassing her . She replied abuse ( nikl bsdk ) . Then her boyfriend calls me ( I don't know she has boyfriend) and he ask me in phone call to kill me by gun and blah blah.. he is constantly harrassing me. I didn't do anything. Help me He know my name by Truecaller. He is constantly harrassing me. He didn't see my face but he has my number