Child hood abuser, contacted me.

I’m not sure if anyone can help or if I’m even asking for help, I’m not quite sure, all I know is my head is exploding. Please I beg do not ask me to see a counsellor, I honestly want to avoid it.
When I was little, my mums boyfriend at the time mooested me, for 3 years, 2 others were also molested, eventually, one spoke out, it all came out. He was convicted and sentenced to jail for approximately 3 years. He had 3 children of his own prior to this. Fast forward just over a decade, I have 3 kids of my own, and created a life, I don’t think a day has past where I haven’t thought about it, but I let myself learn from it, rather then have it define me. I’m the only one of the three assaulted who have children.
Fast forward to a few days ago, I received a message on Facebook, from him. He found me, he messaged me. It was like that second I clicked into my messages, my whole world caught fire. How can someone who had so much control of me, who took my childhood, who took my innocence and who shaped me to be someone who will never trust, nor let my children trust a perfect stranger, now over a decade later, have this much control of me still. I thought he wasn’t aloud to contact me. But apparently, you can molest 3 little girls, get sentenced, serve your sentence and come out at the other end and not be put on a sex offenders list! Not on the child protection registry, nothing. But the known alcoholic down the street was wasted and pissed on a tree next to a primary school and is on the list. A family member (although I don’t condone it) is going to die in prison for growing some pot, but this guy takes so much, changed my life and my outlook on life and the way I raise my children to be aware of things, goes to jail for 3 years and then gets let off Scott free! Where is the justice! Nothing put in place to make it illegal for him to contact me. I was also the only one of us 3 to be contacted, I feel it may be to put more fear in me as i am the only one with children. I can’t get into my car without inspecting it first, I think Ive now started to check on my kids 12 times each through the night, made my partner hook the surveillance cameras up to our bedroom tv so I can see them all night. I’m a god damn adult now, what the fuck. He messages me consistently, for the last few days. You might think why don’t I block him!? Well I can’t, because one of his first messaged me he told me too and I refuse to give him anything he wants, asks or needs. I’m just ignoring him. Everyone keeps telling me to not let him get to me, not to let him in my head, but I don’t know how the hell to do that, I don’t know what to do.
I’ve called police etc and spoken with his parole officer and will be getting a restraining order out. But that doesn’t help what’s happening in my head.