is it a sin?

This life is really2 need to changes whatever happen. As u like or not. however, I’ve just break up with him. its coz of his attitude. he’s cheating on. stabbing on my back. Does I ever stab on his back. does I did something that he does not like/
However, I know who I am. I m not a gorgeous or pretty as my friend.. just a normal person. saitnyer aty ni only god know how it feel. and the latest person I admire, he is searching for a girl which is some kind a modern. the mek kelate friend. ouh. its so hurt. its feel such a really lonely. Only a day he treat me caringly, nicely. emp. but since he saw that girl…I know he has been attract by the girl. what am I thinking. please somebody help me. is it a sin to love someone silently????????