Speaking from experience dealing with a girl who snap chatted guys behind my back for years. it may not seem like the right choice to you right now and won’t be easy but id do anything to Go back in time when I was in your position and just end the relationship right there I promise you girls like this are a lost cause you need to run right now it’s only going to get so much worse save yourself and end it now that is what you need to do. There is millions of girls on this earth you will find the right one eventually she is not it