shitty breakup

Just broke up with my boyfriend of 2 years because I lost feelings. He's currently telling everyone I cheated. He's posting about me on snapchat and calling me a whore. I just don't get how you can go from being in love with someone to this. Literally 2 nights ago he was drunk texting me telling me I'm so special and I mean the world to him now he's saying I cheated and telling me I'm a controller and have no friends. But I'm happy to say my life has taken a huge turn for the better. I've been able to kinda be free and on my own. I had been holding off breaking up with him for so long cuz I knew he would make it a huge issue for me. I just don't really know how to deal with him at this point without him like being rude and stuff. Any advice for dealing with bad breakups?