Harry: You broke up with him because he had no time for you. He was always with Ron and Hermione. You understood they were best friends but he never hung out with you, you didn't see a point in dating him
Ron: you were always second place to Harry. You were tired of dates being canceled so he could go with Harry so you ended it.
Fred: He was always flirting with girls. He was popular with girls but he always told he only loved you. But it's pretty hard to believe that when he was ALWAYS flirting even if you were there, you broke it off when he was heavily flirting with Angelina right in front of you
George: Fred was always with you. You understood that they were twins but sometimes you wanted your boyfriend to yourself. You broke up with him after he came to your date with Fred.
Neville: You always had to make the first move. You were tired of it, you had to do everything! You broke it off when you realized you were never going to kiss until you kissed him, and you were tired of it.
Draco: He was mean to you in front of his friends. He was nice for awhile, but then started teasing you in front of his friends, but he was incredibly sweet alone. You were tired of being teased from your boyfriend
Ginny: She called you clingy. So you just decided to break it off if you were that clingy
Luna: You felt like she never listened to you. You were tired of her never caring about your opinion or anything.
Hermione: She called you stupid
Tom: He was always mean to you. You didnt know if it was because he didnt really love you or if it was because that was just how he acted, but you needed didnt care at this point. You wanted him to have passion when he kissed you, you wanted him to realize that he cant just criticize you casually