my boyfriend has been cheating

So I talk to my boyfriend every single day even tho I went back to school and he stayed in our hometown. So yesterday I found out that he has been talking to some other girl. He put it on snapchat thinking I wasn't going to see and him and the girl said they loved each other and they kissed! I am soooooo angry but very upset and idk what to do. I really love and cannot believe he's done this. And now he knows I know because I blew his phone up sent him screenshots of the snap and everything and he isn't replying but reading it. Idk what to do!!! Help!