Breakup advice?

so my boyfriend and i have been together for almost 4 months. it was originally a serious relationship. we facetimed/call/text all the time, and then once school started back up again our communication slacked off, as expected.
but it's gotten to the point where he only texts me if he needs something, and snapchats me in the morning to keep our streak. it bothered me a lot at first because i know he has time to send me a text. it takes three seconds.
after our most recent fight things just never went back to normal like they usually do. we used to be friends and partners, but now it's just kinda forced.
i find myself annoyed by the things i used to like about him, and i'm just not really attracted to him like i used to be. all his flaws just kinda stick out to me.. like i'm very anti-racism ( i'm native and PR) in any form and he always makes racist jokes, and he once said he n word which really made my blood boil. he's whiter than swiss cheese.
aside from that, he constantly feeds/touches/talks to my service dog which he knows better, and i've told him off a ton of times.
we're supposed to go to homecoming this saturday and after that i really want to break it off. i could use tips since i've never broken up with anybody, just been broken up with 😕