I Am Frustrated

So a few more of my friends have left me. My ex girlfriend has resorted to shaming almost every aspect of me in some attempt to ruin me. Most of what she's saying is just straight up lies, but the amount of people buying it is quite frankly infuriating. I don't know why she's doing this. I've done nothing to deserve this. I'm quite happy to let her live her life but she seems totally against me living mine. I have more important things to focus on. Like college etc. But this just keeps on biting at me. Making me regret even exchanging glances with her in the first place