how to break up with someone nicely?

i feel really bad about breaking up with him:(
weve been going out for about 2 1/2 months, and we were close-ish বন্ধু for a little আরো than a year. we have several things in common, we have the same faith, we both প্রণয় to dance (yes he dances!) and we really try hard to do well in school. well, lately i've been feeling that he doesn't like me as much as he did, because he ditched me for other girls and ignored me sometimes (we don't have any classes together in school) and i've started crushing on another guy (one of my other friends). my situation feels so complicated and i'm planning on breaking up with him tomorrow but i don't know how to, nicely because hes so sweet and kind and sensitive (hes written me a paragraph about why he loves me, and a poem, and hes called me his অ্যাঞ্জেল and is so sweet!..) but i can't stand the thought of breaking up with him অথবা him with another girl.

THE POINT: i feel like i'd rather be good বন্ধু with him, i want to break up with him nicely, &&im crushing on another guy! but i think i have the tiniest feelings for my boyfriend now..

THE QUESTION: what should i do?!?! if i should break up with him, how?! nicely?! hes so sweet..