Ex fiance is Stalking/shit talking me

We were together for 5 years had 3 miscarriages and he left me while I was pregnant last year and since he left he has done nothing but turn ppl against me and shit talked me and my whole family when we did nothing but help him out etc. How do I get this to stop? I'm so annoyed over this. Like come one we're adults now * hes 24 and I'm 22* I haven't said a single bad thing about him since he left out of the blue one night. I later found out he was on meth and lsd. I mean this man literally took me to look at wedding bands the weekend before he left and the day of him leaving talked about getting insurance together so we could get married and to top it off my parents were going to buy him a used car but he left without ever explaining things or anything and as he was about to leave he hugged me then took off running for the front door while still holding on to me and smashed me off the wall causing me to hit my head on a shelf and dragged me to make me hit off the corner of the wall which broke two of my ribs. I ended up miscarrying the next day. he literally left his car and everything at my house and RAN home *he lives 10 mins away* . But I've moved on and I'm over it but why is he still being like this? Why so obsessed on making me look bad to others I care about? Shouldnt I been the one shit talking and all of this bs? Cuz if anyone has hard feelings it should've been me.I did nothing to this man to deserve to be trashed talked on Etc. Someone please help. He drives past my house weekly if not more often. I'm just worried this will never stop. All of this happened with no warning or anything. I still cant wrap my head around it why he did what he did. I mean maybe he jealous that I moved on already? Idk give me yalls opinions and stuff cuz I need this to stop. Thanks for reading this confusing post.