Crazy Ex- Need Advice!

This might be long so bear with me.

I dated this guy back in college on and off for maybe a year and half during my sohpmore/junior years. We broke up because he constantly cheated on me (i was young and stupid at the time) and that was 9 years ago. He was a crazy alcoholic in school and just a mess in general. Anyway after he graduated he disappeared and stopped talking to anyone we went to school with.... except ME! He would text and call me in the middle of the night constantly telling me he was in a mental Hospital and all this crazy shit.

Fast forward to today: im married for two years been with my husband for 7 years and im 34 weeks pregnant. This crazy ex still to this day calls me at least once a year that i know of- im constantly having to block this assholes number and i NEVER communicate back. Its starting to really scare me! He texted me after our wedding and i dont even know how he knew i got married because all my friends and family and me have his ass blocked on all social media. My breaking point was a few weeks ago he called me the night of my BABY SHOWER!!! 😩😩 had to reblock his number like always but im at the point where im fucking PISSED. Idk if its my momma bear instinct coming out and i want to protect my baby and husband from this creep but i want him to fuck right off for good and leave us the hell alone. I got a friend request a few months back from a girl from his hometown... coincidence??? No it was him having her friend me.

So yes the obvious solution is to change my number. Which sucks ass since ive had this number since high school plus working for 7 years but it might be my only option. I could respond back to him and tell him to fuck off and leave us alone but my mom thinks that might fuel his crazy. My husband doesnt like talking about it because it makes him uncomfortable. I mean how would you feel if your hubbys ex from 9 YEARS AGO was still trying to contact him and knew about your life without wanting him to?? And the other issue how he still follows my life somehow and i dont know how hes getting through. I have dreams hes going to show up at our door and kill us😩😩😩

Any advice is greatly appreciated. Im so stressed over this- of all things!!! Im about to have my first baby and this ass is taking up my mental space.