Awww i miss my old boyfriend?

ok i miss my old boyfriend that broke up with me because there is a rumor that i kissed someone and i didnt so he got mad and broke up with me and we were a really good couple. we dated for 9 months and now he changed into a differnt person and i want him back what should i do because i tryed to talk to him but he said bye. i still love him and i truley think there is no one else for me. please help