What can be done about stalker(ish) ex??

An ex from 11 years ago WILL NOT leave me alone to this day. It’s all via social media recently but I do get paranoid and fearful he will one day escalate his stalking again. I call it stalking because he uses all kinds of ways to try to contact me or check on me. I was with him about 3 years and have since gotten happily married and have a child. I have never once responded to any of his methods but he persists. He even somehow was able to pay my tuition one semester while I was still going to the same university as him—which I switched because of him. Over the last years he will randomly try things I’d say about every 3 months or so. I’ve gotten random calls and texts from numbers and I Spokeo them and find it’s registered to him. He used to have access to my personal email which caused a lot of issues obviously and I basically had to close that email and make another with my married name. He somehow has that new email too but not access to the account. I’ll get random password change request emails that I have to deny and change my password constantly. (He does this a lot with my other social media accounts). He sends me emails a lot or puts my email into all kinds of sites to spam it. He has tried to add me on snap chat with his profile and others. I have him and his family blocked on Facebook but he makes fake profiles. He adds me or any of my extended family that will accept. I initially kept his mom as a friend so I could let her know if he was sending me suicide threats but I eventually blocked her because I think he was pretending to be her and messaging me. Since I’ve been with my now husband I have always been sure to keep everything private. I didn’t want him to show up at the wedding or something crazy because I totally believe he would. I only have a public business Instagram separate from my personal and have him blocked but I will always find a fake profile of his when I think about checking. I block and block. After we broke up he would drive by my parents house where I was living and where I worked. Of course I’ve since moved and changed jobs but every once in a while he will let me know he knows some details about those things by liking or commenting on something online. Like my daughters school page posted a public picture and I see he commented on the picture. This is where I freaked out. It had been almost a year since I noticed any activity from him when that happened. I don’t know how to stop this even if I get authorities involved. My husband knows about him being like this but I don’t tell him every little thing I discover because it is just so many little things. I’ve gone so far as to tell my husband that if anything happens to me give the police his name first. Basically, I am constantly thinking about what he knows about me now and now that my child is “involved” I’m even more worried. It’s always in the back of my mind.